Biomedical subjects

D Spiegelman

Publications and source records attributed to D Spiegelman.

At least 145 records · Page 8Linked to original sources

PubMed1997

Variation in the incidence of uterine leiomyoma among premenopausal women by age and race.

OBJECTIVE: To quantify the incidence of uterine leiomyoma confirmed by hysterectomy, ultrasound, or pelvic examination according to age and race among premenopausal women. METHODS: From September 1989 through May 1993, 95,061 premenopausal nurses age 25-44 with intact uteri and no history of uterine leiomyoma were followed to determine incidence rates of uterine leiomyoma. The self-reported diagnosis was confirmed in 93% of the medical records obtained for a sample of cases. Using pooled logistic regression, we estimated relative risks (RRs) of uterine leiomyoma according to race and examined whether adjustment for other potential risk factors could explain the variation in the race-specific rates. RESULTS: During 327,065 woman-years, 4181 new cases of uterine leiomyoma were reported. The incidence rates increased with age, and the age-standardized rates of ultrasound- or hysterectomy-confirmed diagnoses per 1000 woman-years were 8.9 among white women and 30.6 among black women. After further adjustment for marital status, body mass index, age at first birth, years since last birth, history of infertility, age at first oral contraceptive use, and current alcohol consumption, the rates among black women were significantly greater for diagnoses confirmed by ultrasound or hysterectomy (RR 3.25; 95% confidence interval [CI] 2.71, 3.88) and by hysterectomy (RR 1.82; 95% CI 1.17, 2.82) compared with rates among white women. We observed similar RRs when the cohort was restricted to participants who reported undergoing a screening physical examination within the 2 years before baseline. CONCLUSION: A higher prevalence of known risk factors did not explain the excess rate of uterine leiomyoma among premenopausal black women.

Adult↗

PubMed1997

Epidemiologic determinants of endometriosis: a hospital-based case-control study.

PURPOSE: Risk factors for endometriosis were identified through data obtained from a case-control study at Brigham and Women's Hospital in Boston, Massachusetts. METHODS: Cases were 50 women with infertility-associated endometriosis. The primary control group consisted of 89 fertile women without endometriosis, and an alternate control group consisted of 47 infertile women without endometriosis. RESULTS: The risk of endometriosis was positively associated with height (OR), 2.8 per 10 cam increase; 95% confidence interval (CI), 1.4-5.6) and inversely associated with weight (OR, 0.7 per 10 kg increase; 95% CI, 0.5-1.0) and body mass index (OR, 0.7 per 5 kg/m2 increase; 95% CI, 0.4-1.1). We observed an inverse association with exercise (OR, 0.6; 95% CI, 0.3-1.5), but the effect was limited to women who exercised > or = 4 hours per week (OR, 0.4; 95% CI, 0.2-1.2). Endometriosis was not associated with either smoking or alcohol consumption. CONCLUSIONS: Our findings suggest that the fertility status of controls can strongly influence associations seen with menstrual characteristics. This study is one of few to address the issue of control selection for a case-control study of endometriosis. Specifically, potential problems encountered using fertile and infertile control women are examined and discussed.

Adult↗

PubMed1997

Non-dietary factors as risk factors for breast cancer, and as effect modifiers of the association of fat intake and risk of breast cancer.

To assess more precisely the relative risks associated with established risk factors for breast cancer, and whether the association between dietary fat and breast cancer risk varies according to levels of these risk factors, we pooled primary data from six prospective studies in North America and Western Europe in which individual estimates of dietary fat intake had been obtained by validated food-frequency questionnaires. Based on information from 322,647 women among whom 4,827 cases occurred during follow-up: the multivariate-adjusted risk of late menarche (age 15 years or more compared with under 12) was 0.72 (95 percent confidence interval [CI] = 0.62-0.82); of being postmenopausal was 0.82 (CI = 0.69-0.97); of high parity (three or more births compared with none) was 0.72 (CI = 0.61-0.86); of late age at first birth (over 30 years of age compared with 20 or under) was 1.46 (CI = 1.22-1.75); of benign breast disease was 1.53 (CI = 1.41-1.65); of maternal history of breast cancer was 1.38 (CI = 1.14-1.67); and history of a sister with breast cancer was 1.47 (CI = 1.27-1.70). Greater duration of schooling (more than high-school graduation compared with less than high-school graduation) was associated significantly with higher risk in age-adjusted analyses, but was attenuated after controlling for other risk factors. Total fat intake (adjusted for energy consumption) was not associated significantly with breast cancer risk in any strata of these non-dietary risk factors. We observed a marginally significant interaction between total fat intake and risk of breast cancer according to history of benign breast disease; with fat intake being associated nonsignificantly positively with risk among women with a previous history of benign breast disease; no other significant interactions were observed. Risks for reproductive factors were similar to those observed in case-control studies; relative risks for family history of breast cancer were lower. We found no clear evidence in any subgroups of a major relation between total energy-adjusted fat intake and breast cancer risk.

Breast Neoplasms↗

PubMed1997

Regression calibration method for correcting measurement-error bias in nutritional epidemiology.

Regression calibration is a statistical method for adjusting point and interval estimates of effect obtained from regression models commonly used in epidemiology for bias due to measurement error in assessing nutrients or other variables. Previous work developed regression calibration for use in estimating odds ratios from logistic regression. We extend this here to estimating incidence rate ratios from Cox proportional hazards models and regression slopes from linear-regression models. Regression calibration is appropriate when a gold standard is available in a validation study and a linear measurement error with constant variance applies or when replicate measurements are available in a reliability study and linear random within-person error can be assumed. In this paper, the method is illustrated by correction of rate ratios describing the relations between the incidence of breast cancer and dietary intakes of vitamin A, alcohol, and total energy in the Nurses' Health Study. An example using linear regression is based on estimation of the relation between ultradistal radius bone density and dietary intakes of caffeine, calcium, and total energy in the Massachusetts Women's Health Study. Software implementing these methods uses SAS macros.

Adult↗

PubMed1997

A prospective study of NAT2 acetylation genotype, cigarette smoking, and risk of breast cancer.

Polymorphisms in the N-acetyltransferase 2 (NAT2) gene are determinants of the rate of metabolic activation of carcinogenic compounds such as aryl aromatic amines. Homozygosity for any combination of three variant alleles in Caucasians defines 'slow' acetylators; presence of one or two wild-type alleles characterizes 'rapid' acetylators. Although most previous studies have not observed an overall elevation in risk of breast cancer among slow acetylators, a recent study observed that cigarette smoking was associated with a large increase in risk of breast cancer among slow acetylators. We assessed the relation between NAT2 acetylation status and breast cancer risk, and its interaction with smoking, in a prospective study of mainly Caucasian US women. Four hundred and sixty-six incident cases who were diagnosed with breast cancer after giving a blood specimen in 1989-90 were matched to 466 controls in a nested case-control study. NAT2 genotype was determined using PCR-RFLP assays. The multivariate relative risk (RR) comparing slow with rapid acetylators was 0.9 (95% CI 0.7-1.2). Among slow acetylators, current smoking immediately prior to diagnosis was not associated with a significant elevation in risk compared with never smoking rapid acetylators (RR = 1.4, 95% CI 0.7-2.6). No significant association was seen between pack-years of smoking and risk of breast cancer among either slow or fast acetylators. A non-significant elevation in risk was observed among women who smoked for > or = 5 years prior to first pregnancy and were rapid acetylators, compared with never smoking rapid acetylators (RR = 1.5, 95% CI 0.9-2.6). In analyses limited to 706 post-menopausal women, the elevated risks for current smokers immediately prior to diagnosis who were slow acetylators compared with never smokers who were fast acetylators were slightly stronger but still not statistically significant. In summary, we observed little evidence of an association between NAT2 genotype and breast cancer. In this prospective study, cigarette smoking was not appreciably associated with breast cancer among either slow or fast NAT2 acetylators.

Acetylation↗

PubMed1997

Calcium intake and the incidence of forearm and hip fractures among men.

High calcium intakes are thought to be associated with strong bones and lower risk of fractures. However, findings from epidemiologic studies have not been consistent. In addition, the vast majority of such studies were conducted among women, leading to a relative lack of data concerning men. The objective of this study therefore was to investigate the relation between adult calcium intake and risk of fractures among men in the Health Professionals Follow-up Study (HPFS). During 331,234 person-years of follow-up over an 8-y period, 201 forearm and 56 hip fractures due to low or moderate trauma were reported among 43,063 men 40-75 y of age in 1986 when they first completed a questionnaire about diet and lifestyle factors. After controlling for age, smoking status, body mass index (BMI), physical activity, alcohol consumption and total energy intake, the relative risk (RR) of forearm fractures for men in the highest quintile of calcium intake (from foods plus supplements) compared with those in the lowest quintile was 0.98 [95% confidence interval (CI) = 0.59-1.61; P for trend = 0.78]; for hip fractures, the comparable RR was 1.19 (95% CI = 0.42-3.35; P for trend = 0.58). Relative risks for consuming >2.5 glasses (600 mL) of milk per day compared with one (240 mL) or fewer per week were 1.06 (95% CI = 0.69-1.62; P for trend = 0.82) for forearm fractures and 0.97 (95% CI = 0.39-2.42; P for trend = 0.56) for hip fractures. In conclusion, these results do not support a relation between calcium intake and the incidence of forearm or hip fractures in men.

Adult↗

PubMed1997

A prospective study of oral contraceptives and NIDDM among U.S. women.

OBJECTIVE: To examine prospectively the association between modern oral contraceptives with low doses of estrogen and progestin and subsequent incidence of NIDDM. RESEARCH DESIGN AND METHODS: In a prospective cohort study, 98,590 U.S. female nurses aged 25 to 42 and free of diagnosed diabetes, coronary heart disease, stroke, and cancer at baseline in 1989 were followed for 4 years. Endpoint was incidence of confirmed NIDDM. Oral contraceptive use was reported on mailed questionnaires. RESULTS: During 352,067 person-years follow-up, we confirmed 185 incident cases of NIDDM. After adjusting for age, BMI, cigarette smoking, family history of diabetes, parity, physical activity, alcohol intake, ethnicity, history of diagnosis of infertility, elevated cholesterol, and hypertension, women currently using oral contraceptives had a relative risk (RR) of 1.6 (95% CI, 0.9-3.1). For past users, the multivariate RR was 1.2 (95% CI, 0.8-1.8). This association was attenuated after restricting the analysis to symptomatic cases of NIDDM. For current users, RR = 1.3 (95% CI, 0.6-2.8), and for past users, RR = 0.9 (95% CI, 0.6-1.4), suggesting that increased surveillance may explain at least part of any excess risk. CONCLUSIONS: In this large prospective study, we found no appreciable increase in the 4-year risk of NIDDM among current users of oral contraceptives. There was no apparent increase in risk among past users. The small number of cases reflect the low absolute risk of NIDDM in this population of young women.

Adult↗

PubMed1997

Dietary fiber, glycemic load, and risk of NIDDM in men.

OBJECTIVE: Intake of carbohydrates that provide a large glycemic response has been hypothesized to increase the risk of NIDDM, whereas dietary fiber is suspected to reduce incidence. These hypotheses have not been evaluated prospectively. RESEARCH DESIGN AND METHODS: We examined the relationship between diet and risk of NIDDM in a cohort of 42,759 men without NIDDM or cardiovascular disease, who were 40-75 years of age in 1986. Diet was assessed at baseline by a validated semiquantitative food frequency questionnaire. During 6-years of follow-up, 523 incident cases of NIDDM were documented. RESULTS: The dietary glycemic index (an indicator of carbohydrate's ability to raise blood glucose levels) was positively associated with risk of NIDDM after adjustment for age, BMI, smoking, physical activity, family history of diabetes, alcohol consumption, cereal fiber, and total energy intake. Comparing the highest and lowest quintiles, the relative risk (RR) of NIDDM was 1.37 (95% CI, 1.02-1.83, P trend = 0.03). Cereal fiber was inversely associated with risk of NIDDM (RR = 0.70; 95% CI, 0.51-0.96, P trend = 0.007; for > 8.1 g/day vs. < 3.2 g/day). The combination of a high glycemic load and a low cereal fiber intake further increased the risk of NIDDM (RR = 2.17, 95% CI, 1.04-4.54) when compared with a low glycemic load and high cereal fiber intake. CONCLUSIONS: These findings support the hypothesis that diets with a high glycemic load and a low cereal fiber content increase risk of NIDDM in men. Further, they suggest that grains should be consumed in a minimally refined form to reduce the incidence of NIDDM.

Adult↗

PubMed1997

Reduced aliquot size for a plasma organochlorine assay for use in epidemiological studies.

Because archived blood specimens are an important but limited resource for conducting epidemiological studies using biomarkers, it is important to develop analytical techniques that minimize the amount of sample needed. We modified an established 1.0-ml blood plasma organochlorine assay to use smaller volumes. We assessed its utility by comparing the accuracy and precision of measurements obtained with different-sized aliquots of spiked plasma from three pools of known concentration of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and polychlorinated biphenyls (PCBs; low, medium, and high). There was a modest sacrifice in accuracy using 0.5 as opposed to 1.0 ml. However, the within-batch coefficients of variation, a measure of laboratory error, were consistently low when 0.5-ml aliquots were used. For both DDE and PCB concentrations, this error was less than 5% for the medium and high pools [5-20 parts per billion (ng/ml)] and less than 9% for the low pool (< 1 part per billion). After determining that aliquots of 0.5 ml were sufficient, we performed a blinded quality control analysis of stored plasma. In this study, the within-subject variation was low for DDE and PCBs and substantially lower than the between-subject variation, suggesting that the assay would rank subjects with reasonable precision. Our results suggest that use of 0.5-ml as opposed to 1.0-ml aliquots should not compromise the power of a nested case-control study to detect differences between subjects and would thus save plasma for future research. For populations with very low levels of organochlorines, however, the larger volumes should still be used.

Blood Specimen Collection↗

PubMed1997

Fully parametric and semi-parametric regression models for common events with covariate measurement error in main study/validation study designs.

The derivation of the likelihood function for binary data from two types of main study/validation study designs where model covariates are measured with error is elaborated. Rather than limiting consideration to a restricted family of models with convenient mathematical properties, we suggest that empirical considerations, customized to the data at hand, should drive model choices. The joint likelihood function for the main study, in which the covariates are measured with error, and the validation study, in which they are not, is maximized, and estimation and inference proceeds using standard theory. Although the choice of the measurement error model is driven by empirical considerations, the relatively small validation study sizes typically seen may lead to misspecification, resulting in bias in estimation and inference about exposure-disease relationships. By using a nonparametric form for the measurement error model, the resulting semi-parametric methods suggested by Robins, Rotnitzky, and Zhao (1994, Journal of the American Statistical Association 89, 864-866) and Robins, Hsieh, and Newey (1995, Journal of the Royal Statistical Society, Series B 57, 409-424) are free from bias due to misspecification of the measurement error model, trading efficiency for robustness as usual. These fully and semi-parametric methods are illustrated with a detailed example from a main study/validation study of the health effects of occupational exposure to chemotherapeutics among pharmacists (Valanis et al., 1993, American Journal of Hospital Pharmacy 50, 455-462). A constant, prevalence ratio model for common binary events, with gamma covariate measurement error, is derived and empirically verified by the available data. A careful reanalysis of the data, taking measurement error fully into account, leads to a threefold increase in the log relative risk and no loss of statistical power. The semi-parametric estimates are consistent with the parametric results, providing reassurance that important bias due to misspecification of the measurement error model is unlikely.

Analysis of Variance↗

PubMed1997

Glutathione S-transferase class mu deletion polymorphism and breast cancer: results from prevalent versus incident cases.

A common deletion polymorphism in the gene coding for the glutathione S-transferase class mu (the GSTM1 gene) results in a decreased ability to detoxify carcinogenic epoxide intermediates and has been associated with increased breast cancer risk in some small studies. We studied the GSTM1 gene deletion polymorphism (conferring the null genotype) in 243 women who had prevalent breast cancer and 245 women without breast cancer, who were among the 32,826 women in the Nurses' Health Study who gave a blood sample in 1989-1990. In the prevalent case series, the null genotype was slightly more common among cases (58%) than among controls (51%; age-adjusted odds ratio = 1.30; 95% confidence interval, 0.91-1.86). Among cases, the prevalence of the GSTM1 deletion increased with duration of survival [68% for > or = 8 years since diagnosis; 57% for 4-8 years; 51% for < 4 years; P (trend) = 0.04]. In an incident case series of 240 women who were diagnosed with breast cancer following blood collection and prior to June of 1992 and compared with age-matched controls, the GSTM1 deletion was not associated with an elevation in risk (relative risk, 1.08; 95% confidence interval, 0.74-1.57). No significant interaction with cigarette smoking was evident. Thus, there was no significant increase in risk of incident breast cancer associated with the GSTM1 null genotype; however, the gene deletion polymorphism appeared to confer improved survival. These data suggest that odds ratios based upon prevalent cases in molecular epidemiologic studies may be biased due to differential survival. Further studies are required to determine whether this polymorphism is associated with improved breast cancer prognosis.

Adult↗

PubMed1996

Birth weight and adult hypertension, diabetes mellitus, and obesity in US men.

BACKGROUND: Low birth weight has been associated with several chronic diseases in adults, including hypertension, diabetes mellitus, and obesity. Further study of these diseases in a large cohort with information on a wide variety of risk factors is essential to determine more precisely the risks associated with birth weight. METHODS AND RESULTS: We examined the relation between birth weight and cumulative incidence of adult hypertension, incidence of non-insulin-dependent diabetes mellitus, and prevalence of obesity in a cohort of 22,846 US men (Health Professionals Follow-up Study). Birth weights, medical histories, family histories, and other factors were collected by biennial mailed questionnaires. Logistic regression was used to examine the association between birth weight and these chronic adult diseases. Low birth weight was associated with an increased risk of hypertension and diabetes; high birth weight was associated with an increased risk of obesity. Compared with men in the referent birth weight category (7.0 to 8.4 lb), men who weighed < 5.5 lb had an age-adjusted odds ratio for hypertension of 1.26 (95% confidence interval [CI], 1.11 to 1.44) and for diabetes mellitus of 1.75 (95% CI, 1.21 to 2.54). There was no material change after controlling for adult body mass index and parental histories of hypertension and diabetes mellitus. Compared with men in the referent group, the age-adjusted odds ratio of being in the highest versus the lowest quintile of adult body mass index for men with birth weight > or = 10.0 lb was 2.08 (95% CI, 1.73 to 2.50). CONCLUSIONS: These findings support the hypothesis that early life exposures, for which birth weight is a marker, are associated with several chronic diseases in adulthood.

Adult↗

PubMed1996

Human immunodeficiency virus infection in Mexico City. Rectal bleeding and anal warts as risk factors among men reporting sex with men.

The objectives of this study were to evaluate the frequency and determinants of rectal bleeding and the association between rectal bleeding and risk of human immunodeficiency virus (HIV) infection among homosexual/ bisexual men in Mexico City. Men who requested anonymous HIV testing at a public clinic in Mexico City and who reported engaging in any homosexual behavior were eligible to participate in this study. Trained staff collected information on demographic factors, sexual behavior, psychological states, and HIV serostatus from all consenting, eligible clients. Logistic regression modeling was used to investigate the independent effect of risk factors among 2,758 men who were tested between June 1991 and December 1992. Bleeding during anal intercourse was a common occurrence: More than one third of the men in the study reported some bleeding, and 8% reported bleeding in half or more of their intercourse episodes. The prevalence of HIV infection among bleeders was 42% as compared with 28% in nonbleeders (p < 0.0001), and the adjusted odds ratio was 1.8 (95% confidence interval (CI) 1.1-2.8) for men who bled in more than half of their anal intercourse episodes relative to nonbleeders. There was a trend of increasing HIV seroprevalence with increasing frequency of rectal bleeding (p = 0.001). Nine percent of all HIV infections and 42% of infections among frequent bleeders were attributable to rectal bleeding. Men who reported both rectal bleeding and anal warts were 3.5 (95% CI 2.1-5.8) times more likely to be HIV-infected in multivariate analysis than men reporting neither rectal bleeding nor anal warts. Determinants of rectal bleeding included older age, more education, more receptive anal intercourse than insertive intercourse, receptive digital-anal contact, anal warts, and genital ulcers. Among men reporting sex with men in Mexico City, rectal bleeding is common. It is an independent risk factor for HIV infection, and warrants attention in acquired immunodeficiency syndrome prevention efforts. Rectal bleeding that results from rupture of anal warts may be an especially effective portal of HIV transmission.

Adult↗

PubMed1996

A methylenetetrahydrofolate reductase polymorphism and the risk of colorectal cancer.

We examined the relationship of a common polymorphism (667C-->T) of the methylenetetrahydrofolate reductase (MTHFR) gene with the risk of colorectal cancer in a case-control study conducted in the Health Professionals Follow-up Study. MTHFR genotypes were ascertained from blood samples among 144 men previously diagnosed with colorectal cancer and 627 controls. The adjusted odds ratio (OR) for the MTHFR variant homozygous (val/val) genotype was 0.57 [95% confidence interval (CI), 0.30-1.06]. High dietary intake of methionine (OR, 0.27; 95% CI, 0.06-1.20) and low consumption of alcohol (OR, 0.11; 95% CI, 0.01-0.85) were associated with reduced incidence of colorectal cancer. Alcohol intake was a stronger risk factor among men with the val/val genotype (P, trend = 0.01), and consumption of five or more alcoholic drinks per week abolished the reduced risk of colorectal cancer among val/val individuals (P, interaction = 0.02). The inverse association of methionine with colorectal cancer risk was slightly stronger among individuals with the MTHFR val/val genotype. These data suggest that dietary methyl supply is particularly critical among MTHFR val/val individuals. When dietary methyl supply is high, MTHFR val/val individuals may be at reduced risk of colorectal cancer probably because higher levels of 5,10-methylenetetrahydrofolate may prevent imbalances of nucleotide pools during DNA synthesis. In contrast, when 5-methyltetrahydrofolate is depleted by alcohol consumption, val/val individuals may be less able to compensate, leading to potentially oncogenic alterations in DNA methylation.

Adult↗

PubMed1996

Hormone levels during dietary changes in premenopausal African-American women.

BACKGROUND: In the United States, 5-year survival rates of 69% and 84%, respectively, have recently been reported for African-American and Caucasian women diagnosed with breast cancer. Differences in the levels of endogenous sex hormones in these populations could explain some of the variation in survival rates, since estrogen is recognized as a risk factor for this type of cancer. PURPOSE: Dietary factors are known to affect endogenous hormone levels; therefore, our study was designed to determine the serum hormone levels of African-American women consuming a typical North American diet, to determine the effect of a low-fat and high-fiber diet on their serum hormone levels, and to compare the base-line serum hormone levels in the African-American women with hormone data from our study of Caucasian women (n = 68) consuming the same control diet. METHODS: Twenty-one healthy, premenopausal, African-American women who agreed to eat only food prepared in a clinical study unit were recruited into the study. The control diet was similar to their usual diet, being high in fat (40% of calories from fat) and low in fiber (12 g/day), and was consumed on average for 3 weeks. The concentrations of estrone (E1), estrone sulfate (E1SO4), estradiol (E2), free E2, androstenedione, and sex hormone-binding globulin (SHBG) in serum samples obtained from the participants during the last week of the control diet and during the follicular phase of their menstrual cycle were determined. The women were then switched to a diet low in fat (20% of calories as fat) and high in fiber (40 g/day); they consumed this diet for two menstrual cycles before blood samples were collected for determination of serum hormone levels. Repeated-measures regression modeling was used to investigate the relationship between diet and hormone levels in African-American and Caucasian women. All P values resulted from two-sided statistical tests. RESULTS: Analysis of serum hormone levels in the African-American women indicated that the change in diet caused a significant decrease in E2 (-8.5%; 95% confidence interval [CI] = -16.1% to -0.3%; P < or = .03) and E1SO4 (-16.2%; 95% CI = -22.1% to -9.8%; P < .0001) and a significant increase in androstenedione levels (+18.3%; 95% CI = +10.3% to +26.8%; P < .0001). SHBG levels of the African-American women were 5.6% (95% CI = -14.0% to +3.7%) lower for those on the experimental diet compared with those on the control diet, but the difference was not statistically significant. Comparison of control serum hormone values in the African-American women in this study with those in Caucasian women previously studied indicated that the Caucasian women had statistically significant lower levels of E1 (-37%; 95% CI = -61.2% to -16.4%; P < or = .0002), E2 (-54.5%; 95% CI = -90.9% to -25.1%; P < or = .0001), free E2 (-30.2%; 95% CI = -65.7% to -2.3%; P < .03), and androstenedione (-48.3%; 95% CI = -83.7% to -19.7%; P < or = .0004). CONCLUSION: African-American women appear to have higher levels of serum hormones than Caucasian women, and dietary modification can result in a lowering of serum estrogens.

Adult↗

PubMed1996

Birth weight and adult hypertension and obesity in women.

BACKGROUND: Low birth weight has been associated with an increased risk of hypertension, and high birth weight has been associated with increased adult body mass index. Published studies on adults have included only a small number of women. METHODS AND RESULTS: We studied 71 100 women in the Nurses Health Study I (NHS I) who were 30 to 55 years of age in 1976 and 92 940 women in the Nurses' Health Study II (NHS II) who were 25 to 42 years of age in 1989. Information on birth weight, blood pressure, physician-diagnosed hypertension, and other relevant variables was collected by biennial mailed questionnaire. Ninety-five percent of the women were white. Compared with women in the middle category of birth weight (NHS I, 7.1 to 8.5 lb; NHS II, 7.0 to 8.4 lb), the age-adjusted odds ratio of hypertension in NHS I women with birth weights < 5.0 lb was 1.39 (95% CI, 1.29 to 1.50); in NHS II, for birth weights < 5.5 lb, the age-adjusted odds ratio was 1.43 (95% CI, 1.31 to 1.56). There was no material change in the estimates after adjustment for other risk factors. In addition, compared with women in NHS I who weighed 7.1 to 8.5 lb at birth, those who weighed > 10 lb had an age-adjusted odds ratio of 1.62 (95% CI, 1.38 to 1.90) of being in the highest (> 29.2 kg/m2) versus the lowest (< 21.9 kg/ m2) quintile of body mass index in midlife. Similar results were seen in the NHS II cohort. CONCLUSIONS: Early life exposures affecting birth weight may be important in the development of hypertension and obesity in adults.

Adult↗

PubMed1996

Determinants of HIV infection among female commercial sex workers in northeastern Thailand: results from a longitudinal study.

Our objective was to estimate HIV seroconversion rates among commercial sex workers (CSWs) between 1990 and 1991 and to identify the behavioral, demographic, and reproductive determinants of these rates. This study has a prospective (n = 240 with 15 cases) and a cross-sectional component (n = 271 with 34 cases). In November 1990, HIV-negative female CSWs from 24 brothels in Khon Kaen city were interviewed and were followed prospectively for up to 1 year. In March, June, and September 1991, additional HIV-negative CSWs were enrolled and prospectively followed. HIV seroconversion rates were calculated, and the Cox regression model was used to estimate the relative risks of HIV seroconversion from demographic, sexual practice, and reproductive factors, adjusted for the effects of the others, among 232 of the 240 without missing data. Seroprevalence rates were also calculated for the 271 participants enrolled between March and December 1991, and relative risks of HIV seroprevalence were calculated for demographic, sexual practice, and reproductive risk factors among 184 of the 271 without missing data. The average seroprevalence was 12.5% (95% confidence interval 9.6-15.4%). With 1,947 person-months of observation obtained from 240 participants who were uninfected at baseline and seen at least twice during the course of the study, the cumulative incidence of HIV seroconversion between November 1990 and December 1991 was 9.4% (95% confidence interval 5.4-13.4%), and the average incidence rate of HIV seroconversion was 9.2 per 100 person-years (95% confidence interval 4.6-13.9 per 100 person-years). In the multivariate analysis, later date of enrollment into the study, having < 3 months experience as a CSW, and use of injectable contraceptives were the only risk factors that remained significant, with relative risks of 2.1 (95% confidence interval 1.2-3.7) for enrollment 3 months later, 3.8 (95% confidence interval 1.0-14.4) for < 3 months experience as a CSW versus > 3 months experience, and 3.9 (95% confidence interval 1.3-11.8) [corrected] for use of injectable contraceptives. In multivariate analysis of the cross-sectional data with 184 participants, of whom 21 were HIV seropositive, risk of HIV seropositivity increased significantly with current syphilis infection (odds ratio 5.8, 95% confidence interval 1.1-31.0). The results of this study will contribute to a better understanding of the risk factors of infection with HIV and thus allow for better targeting of group-specific interventions, particularly for CSWs and their clients. Further investigation of a possible association between injectable contraceptive use and HIV infection is needed.

Adolescent↗

PubMed1996

Prospective study of oral contraceptives and hypertension among women in the United States.

BACKGROUND: Oral contraceptives induce hypertension in approximately 5% of users of high-dose pills that contain at least 50 micrograms estrogen and 1 to 4 mg progestin, and small increases in blood pressure have been reported even among users of modern low-dose formulations. However, neither the responsible hormone in the oral contraceptive nor particular subgroups of women who might be susceptible to the hypertensive effect of oral contraceptives have been identified. METHODS AND RESULTS: In a prospective cohort study in the United States, 68 297 female nurses aged 25 to 42 years and free of diagnosed hypertension, diabetes, coronary heart disease, stroke, and cancer at baseline were followed up for 4 years. During 231 006 person-years of follow-up, 1567 incident cases of hypertension were diagnosed. Compared with women who had never used oral contraceptives, the age-adjusted relative risk was 1.5 (95% CI = 1.2 to 1.8) for current use and 1.1 (95% CI = 0.9 to 1.2) for past use. After adjustment for age, body mass index, hormones cigarette smoking, family history of hypertension, parity, physical activity, alcohol intake, and ethnicity, current users of oral contraceptives had an increased risk of development of hypertension (RR = 1.8; 95% CI = 1.5 to 2.3) compared with women who had never used them. The multivariate relative risk for past users was 1.2 (95% CI = 1.0 to 1.4). There were no important modifying effects of age, family history of hypertension, ethnicity, or body mass index. CONCLUSIONS: Current users of oral contraceptives had a significant, moderately increased risk of hypertension. However, among this group, only 41.5 cases per 10 000 person-years could be attributed to oral contraceptive use. Risk decreased quickly with cessation of oral contraceptives, and past users appeared to have only a slightly increased risk.

Adult↗