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L Lipworth

Publications and source records attributed to L Lipworth.

At least 19 recordsLinked to original sources
PubMed2003

Maternal and gestational correlates of pregnancy prolactin and growth hormone in USA and China.

The objective of this study is to determine correlates of prolactin and growth hormone levels among pregnant women in the USA and China. We studied 304 pregnant Caucasian and 335 pregnant Chinese women. Levels of prolactin and growth hormone were measured at weeks 16 and 27 of gestation, and correlated with maternal, gestational and perinatal characteristics. Both growth hormone and, to a lesser extent, prolactin were inversely associated with pregnancy weight and body mass index, history of a previous live birth and newborn size, whereas educated women had higher levels of both hormones. Growth hormone levels were lower in women who gained more weight, smoked and had nausea and vomiting during pregnancy, whereas prolactin increased with longer total gestation. We found robust associations between maternal and newborn characteristics on the one hand and prolactin and growth hormone during pregnancy on the other.

Adult↗
PubMed2003

Occupational exposure to vinyl chloride and cancer risk: a review of the epidemiologic literature.

Occupational exposure to vinyl chloride (VC) is causally related to liver angiosarcoma, whereas there is inconsistent epidemiologic evidence for other neoplasms. Two pooled analyses of worker cohorts from 56 plants in North America and Europe provide the most comprehensive and updated data on cancer risk among workers exposed to VC. These included over 22,000 workers, with a total of 640,000 person-years of observation, followed-up for up to 50 years. Overall, a total of 1,778 cancer deaths were observed versus 1,829.46 expected, corresponding to a standardized mortality ratio (SMR) of 0.97 (95% confidence interval (CI)=0.93-1.02). Excluding 71 confirmed angiosarcomas, there were 60 deaths from liver cancers versus 44.35 expected (SMR=1.35, 95% CI=1.03-1.74). Lung and laryngeal cancer mortality were significantly lower than expected (SMR=0.88 and 0.59, respectively). The SMRs for soft tissue sarcoma, brain, lymphoid and haematopoietic system cancers were not materially different from unity. Thus, the aggregate data from over 20,000 VC workers in North America and Europe exclude any excess mortality from lung, laryngeal, soft tissue sarcoma, brain, lymphoid and haematopoietic neoplasms. There appears to be a slight excess of liver cancer other than angiosarcoma, which is difficult to interpret and is likely due to residual misclassification of angiosarcomas.

Cohort Studies↗
PubMed2002

Correlates of pregnancy oestrogen, progesterone and sex hormone-binding globulin in the USA and China.

The objective of this study is to examine perinatal correlates of oestradiol (E2), oestriol (E3), progesterone and sex hormone-binding globulin (SHBG) among pregnant women in the USA and China. Three hundred and four Caucasian women in Boston and 335 Chinese women in Shanghai were studied. Levels of E2, E3, progesterone and SHBG were measured in maternal blood at weeks 16 and 27 of gestation, and correlated with maternal, gestational and perinatal characteristics. Height, weight and body mass index (BMI) before pregnancy is inversely associated with E2 and SHBG, whereas E3 is inversely associated with height and progesterone is inversely associated with weight and BMI. A previous live birth is associated with lower E2 and SHBG in the index pregnancy. Total gestation duration is inversely associated with E2, E3 and progesterone, whereas weight gain during pregnancy is inversely associated with progesterone and SHBG. In the US, pregnancies with female fetuses are characterized by significantly reduced progesterone. Pregnancy hormones are associated with several maternal, gestational and neonatal characteristics.

Adult↗
PubMed2001

Acetaminophen, aspirin, and chronic renal failure.

BACKGROUND: Several epidemiologic studies have demonstrated an association between heavy consumption of nonnarcotic analgesics and the occurrence of chronic renal failure, but it is unclear which is the cause and which is the effect METHODS: In a nationwide, population-based, case-control study of early-stage chronic renal failure in Sweden, face-to-face interviews were conducted with 926 patients with newly diagnosed renal failure and 998 control subjects, of whom 918 and 980, respectively, had complete data. We used logistic-regression models to estimate the relative risks of disease-specific types of chronic renal failure associated with the use of various analgesics RESULTS: Aspirin and acetaminophen were used regularly by 37 percent and 25 percent, respectively, of the patients with renal failure and by 19 percent and 12 percent, respectively, of the controls. Regular use of either drug in the absence of the other was associated with an increase by a factor of 2.5 in the risk of chronic renal failure from any cause. The relative risks rose with increasing cumulative lifetime doses, rose more consistently with acetaminophen use than with aspirin use, and were increased for most disease-specific types of chronic renal failure. When we disregarded the recent use of analgesics, which could have occurred in response to antecedents of renal disease, the associations were only slightly attenuated CONCLUSIONS: Our results are consistent with the existence of exacerbating effects of acetaminophen and aspirin on chronic renal failure. However, we cannot rule out the possibility of bias due to the triggering of analgesic consumption by predisposing conditions.

Acetaminophen↗
PubMed2001

Nationwide study of cancer risk among hip replacement patients in Sweden.

BACKGROUND: Orthopedic implants and their fixatives contain materials with carcinogenic potential. Whether these implants are linked to subsequent cancer development remains unknown, mainly because large-scale, long-term follow-up data are scarce. METHODS: We conducted a nationwide cohort study in Sweden to examine cancer incidence among 116,727 patients who underwent hip replacement surgery during the period from 1965 through 1994. Through record linkage to the Swedish Cancer Register, we identified all incident cancers through 1995 in this population (693,954 person-years of observation). For each cancer type, the observed number of cases was divided by that expected in the general Swedish population to produce standardized incidence ratios (SIRs). RESULTS: Relative to the general population, the cohort had no overall cancer excess (SIR = 1.01; 95% confidence interval [CI] = 0.99 to 1.03). However, we observed elevated SIRs for prostate cancer (SIR = 1.16; 95% CI = 1.11 to 1.22) and melanoma (SIR = 1.15; 95% CI = 1.01 to 1.30) and a reduction in stomach cancer risk (SIR = 0.83; 95% CI = 0.75 to 0.92). Long-term follow-up (>or=15 years) revealed an excess of multiple myeloma (SIR = 1.86; 95% CI = 1.01 to 3.11) and a statistically nonsignificant increase in bladder cancer (SIR = 1.42; 95% CI = 0.98 to 1.99). There was no material increase in risk for bone or connective tissue cancer for either men or women in any follow-up period. CONCLUSIONS: In this, the largest study to date, hip implant patients had similar rates of most types of cancer to those in the general population. Although the excesses of melanoma, multiple myeloma, and prostate and bladder cancers may be due to chance, confounding, or detection bias and should be interpreted cautiously, they warrant further investigation because of the ever-increasing use of hip implants at younger ages.

Aged↗
PubMed2001

Connective tissue disease and other rheumatic conditions following cosmetic breast implantation in Denmark.

OBJECTIVE: To examine the occurrence of connective tissue diseases (CTDs) as well as ill-defined and other rheumatic conditions among Danish women with cosmetic silicone breast implants. PATIENTS AND METHODS: A total of 2761 women with breast implants and 8807 control subjects were identified from plastic surgery private clinics and from public hospital plastic surgery departments. Women operated on at plastic surgery private clinics were identified through the files of each clinic, while women operated on at public hospitals were identified using the nationwide Danish National Registry of Patients. The control group consisted of women who underwent cosmetic surgery other than breast implantation or who only had a consultation. All women were followed up from January 1, 1977, through December 31, 1996, through the Danish National Registry of Patients for the occurrence of CTD as well as ill-defined and other rheumatic conditions. For the study period January 1, 1977, through December 31, 1994, the Danish National Registry of Patients contains information on hospitalization only, whereas data on outpatient visits are included from 1995 on, thus improving the sensitivity of the data. The implant and control groups were compared with the Danish population rates for CTD and ill-defined and other rheumatic conditions, and a direct comparison between the implant and control groups was also performed. RESULTS: When compared with rates from the general population, no excess of definite CTD was observed in the implant cohorts. For ill-defined and other rheumatic conditions, statistically significant excesses of unspecified rheumatism were observed in both the implant and control cohorts when compared with national rates. A direct comparison between the implant and control cohorts found no material differences between the groups. CONCLUSIONS: The findings of this study support previous investigations and independent review panel conclusions that an association between silicone breast implants and definite CTDs is unlikely. The observation of an excess of unspecified rheumatism among women with implants and among control women suggests that women undergoing cosmetic plastic surgery have hospitalization rates for this condition in excess of those from the general population.

Adolescent↗
PubMed2001

A critical evaluation of the scientific basis of the MAK Commission's new general threshold limit values for dust.

In 1997, the German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area set a new MAK value ("Maximale Arbeitsplatz-Konzentration") governing worker exposures to general airborne dust. The new values limit worker dust exposures to concentrations not exceeding 1.5 mg/m3 for respirable dust and 4 mg/m3 for inhalable dust, and are substantially lower than corresponding standards in other western industrialized nations. The purpose of this document is to critically review the science behind the MAK Commission's new threshold limit value standards. The Commission relied heavily upon a re-analysis of data from the Deutsche Forschungsgemeinschaft (DFG) Chronic Bronchitis study (1965-1977). We have reservations about the scientific merit of the DFG study and the validity of data used as the basis for establishing a new MAK value for dust. In particular: (1) Assessing the potential role of inert dust in the development of chronic bronchitis in worker cohorts with extremely high cigarette smoking prevalences is scientifically implausible. (2) It is unlikely that the dust in the industries studied, including steel works, foundries and cement works, was in fact "inert", and any effects of the dust on chronic bronchitis rates may have been increased by the presence of free crystalline silica and other toxic agents. (3) The study made use of area- rather than personal-exposure monitoring, thereby correlating the prevalence of chronic bronchitis with lower dust exposure levels than actually existed and significantly overstating the health effects of the dust exposures. (4) Inappropriate statistical methods were used to estimate threshold limit values. Results of three additional epidemiological studies are cited as providing evidence of chronic lung effects due to insoluble dust exposure. All three studies suffer from extremely poor documentation of the study methodology, particularly regarding lung function testing, and they provide little evidence that exposure to insoluble non-fibrogenic dusts leads to chronic lung obstruction. In summary, it is our opinion that the studies evaluated by the MAK Commission and the methods used do not provide the scientific basis to support the lower threshold limit values for dust. We recommend that an appropriate prospective morbidity study be conducted to address the concerns detailed in this critical examination.

Bronchitis↗
PubMed2001

Rheumatic manifestations in danish women with silicone breast implants.

The aim of this study was to investigate whether women with silicone breast implants (SBI) present with a unique rheumatic symptomatology. We assessed the profile of rheumatic disease in six groups of women identified through Danish hospital and population registers, three groups of women with a prior hospital diagnosis of muscular rheumatism (a non-specific diagnostic code) who had previously undergone SBI surgery (n = 28), breast reduction surgery (n = 29) or no breast surgery (n = 27); and three groups of women without a diagnosis of muscular rheumatism who had undergone SBI surgery (n = 21), breast reduction surgery (n = 27) or no breast sugery (n = 56). All women in the study population (n = 188) underwent a thorough clinical examination, blood tests and a personal interview. In all study groups soft-tissue rheumatism and degenerative diseases were the most frequent diagnoses. Women with a prior diagnosis of muscular rheumatism but no prior breast surgery had a significantly higher prevalence of soft-tissue rheumatism than those with breast implant or reduction surgery. No significant differences in the frequencies of rheumatic diseases were observed among the three groups of women without previous muscular rheumatism. No specific pattern of inflammatory rheumatic disorders or soft-tissue complaints was identified among the women with SBI, and blood tests for autoimmunity revealed no unique pattern. Overall, women with earlier rheumatism had significantly increased frequencies of rheumatic conditions than did those without. We found no evidence of a rheumatic symptomatology unique to women with silicone breast implants. Our study emphasises the need for consideration of prior rheumatic disease when evaluating rheumatic manifestations in women with SBI.

Adult↗
PubMed2001

Neurological disease among women with silicone breast implants in Denmark.

OBJECTIVES: To investigate the risk of neurological disease among women with cosmetic breast implants. MATERIAL AND METHODS: We identified 1,653 women who had undergone breast implant surgery at private clinics in Denmark and a comparison cohort of 1,736 women who underwent other types of cosmetic surgery at the same clinics. Ratios of observed-to-expected numbers of hospitalizations for neurological disease in the private implant and comparison cohorts were calculated, separately and combined with data from updated public hospital cohorts. RESULTS: The occurrence of neurological disease in the private clinic implant cohort was comparable to that in the general population. A similar risk pattern was observed in the private clinic comparison cohort. When data for these private clinic cohorts were combined with updated data for public hospital cohorts, excess risks for neurological disorders were seen in both implant and comparison cohorts, reaching statistical significance only in the comparison cohort. CONCLUSION: Our findings indicate no causal association between silicone breast implants and neurological disease.

Adult↗
PubMed2001

Comparison of surrogate with self-respondents regarding medical history and prior medication use.

BACKGROUND: The self-report of medical history and medication use is a common feature of epidemiological research. METHODS: In a unique re-interview study, we evaluated the concordance of medical conditions and past medication use reported in two similar interviews 5 years apart. RESULTS: In 196 re-interviews with the subjects themselves, and in 107 with next-of-kin of subjects who died after the first interview, agreement was good or excellent (kappa > or =0.40) for 90% (9/10) of the conditions asked about in the personal medical history for both next-of-kin and self-respondents. Agreement was excellent (kappa >0.75) for two conditions, high blood pressure and hysterectomy, among self-respondents. Self- and surrogate respondents also showed similar reproducibility for prescription medications, but next-of-kin respondents tended to have poor agreement (kappa <0.40) for over-the-counter (OTC) medications such as antacids, antihistamines, and analgesics. Next-of-kin also less reliably reported a family history of cancer. When analyses were stratified by type of surrogate respondent, concordance between the two interviews was generally higher for spouses than for other surrogate respondents. CONCLUSIONS: This research demonstrates that personal medical history and prescription medication use may be as reliably reported by next-of-kin as self-respondents, but suggests that additional information may be needed to validate measures of OTC medication use and family history of cancer for next-of-kin respondents, possibly through the review of hospital records.

Adult↗
PubMed2001

Capsular contracture after cosmetic breast implant surgery in Denmark.

The authors investigated the association between the occurrence of capsular contracture and implant and patient characteristics. All women with breast implants from 1977 to 1997 were identified from the files of two private plastic surgery clinics in Denmark. Information on implant and patient characteristics, surgical procedure, and complications was obtained through medical records and self-administered questionnaires. Of 754 women (1,572 implants), average age at implantation was 32 years. Implant types were silicone double lumen, textured, 31.2%; silicone single lumen, textured, 27.8%; silicone single lumen, smooth, 24.5%; silicone double lumen, smooth, 0.8%; and other or missing, 15.7%. Placement was submuscular for more than 90% of implants. Capsular contracture occurred in 7.9% of implanted breasts, on an average of 621 days postoperatively, with 51.6% being bilateral. Overall, 66.1% of capsular contractures were recorded within the first 12 months postoperatively, and 79.0% were recorded within 24 months. Double-lumen implants were associated with a significantly (p < 0.01) reduced occurrence of capsular contracture. In summary, capsular contracture typically occurs within the first 2 years of implantation. Host factors may be important because more than half the capsular contractures in the current study were bilateral. Occurrence of capsular contracture did not appear to be associated with implant surface or placement, occurrence of local complications, or patient characteristics, although these findings should be interpreted cautiously.

Adult↗
PubMed2001

Multiple sclerosis and age at infection with common viruses.

Increased risk of multiple sclerosis has been reported among individuals with a history of measles and other common childhood diseases during adolescence, infectious mononucleosis, or exposure to the canine distemper virus. We investigated these associations in a case-control study nested within the Nurses' Health Study (121,700 women traced since 1976) and the Nurses' Health Study II (116,671 women traced since 1989). Age at diagnosis of common viral diseases and birth order were obtained through a questionnaire. Our results include 301 cases with multiple sclerosis and their (up to six) matched controls. Except for infectious mononucleosis, which was a moderate risk factor (odds ratio = 2.1, 95% confidence interval = 1.5-2.9), we found little association between history of common viral diseases or exposure to canine distemper virus and risk of multiple sclerosis. We did find a relation between mumps after 15 years of age (odds ratio = 2.3, 95% confidence interval = 1.2-4.3) or measles after age 15 years of age (odds ratio = 2.8, 95% confidence interval = 0.8-9.1) and multiple sclerosis. Birth order was not materially related to multiple sclerosis. Our findings support the hypothesis that individuals who suffered from infectious mononucleosis, a marker of late infection with the Epstein-Barr virus, have an increased risk of multiple sclerosis. Late infection with other common viruses may also be associated with increased risk.

Adult↗
PubMed2001

Local complications and subsequent symptom reporting among women with cosmetic breast implants.

Epidemiologic studies have found no association between breast implants and cancer or well-defined connective tissue diseases. However, women with cosmetic breast implants continue to report specific as well as nonspecific physical and psychological symptoms after receiving their implants. In an attempt to determine whether local complications of implantation may contribute to this excess of symptom reporting, the authors studied a large cohort of women in Sweden with cosmetic breast implants (n = 1280) and a comparison cohort of women who had cosmetic breast reduction surgery (n = 2211). Both groups of women had operations between 1969 and 1996. Medical record reviews of local complications revealed that approximately 31 percent of the women with cosmetic breast implants had an implant change, implant leakage, or a capsulotomy. Capsulotomies occurred more often in women who were age 35 or older at the time of the operation, had ever smoked, and had implants with a smooth surface. On self-administered questionnaires, symptoms were reported more often by the women who had implants regardless of whether they had local complications. Twenty of the 28 symptoms occurred more frequently among women with local complications and breast implants, compared with the women in the breast reduction comparison group or the women with breast implants but no local complications. This study suggests that local complications, particularly capsular contractures as indicated by capsulotomy, may be an important factor to consider when studying symptom reporting among women with breast implants.

Adult↗
PubMed2001

Cancer incidence among Danish workers exposed to trichloroethylene.

Human evidence regarding the carcinogenicity of the animal carcinogen trichloroethylene (TCE) is limited. We evaluated cancer occurrence among 803 Danish workers exposed to TCE, using historical files of individual air and urinary measurements of TCE-exposure. The standardized incidence ratio (SIR) for cancer overall was close to unity for both men and women who were exposed to TCE. Men had significantly elevated SIRs for non-Hodgkin's lymphoma (SIR = 3.5; n = 8) and cancer of the esophagus (SIR = 4.2; n = 6). Among women, the SIR for cervical cancer was significantly increased (SIR = 3.8; n = 4). No clear dose-response relationship appeared for any of these cancers. We found no increased risk for kidney cancer. In summary, we found no overall increase in cancer risk among TCE-exposed workers in Denmark. For those cancer sites where excesses were noted, the small numbers of observed cases and the lack of dose-related effects hinder etiological conclusions.

Denmark↗
PubMed2000

Genetic effects on the liability of developing pre-eclampsia and gestational hypertension.

Genetic factors are known to be important in the etiology of pre-eclampsia and possibly also gestational hypertension, but the degree of genetic influence has not been quantified. To estimate the genetic and environmental effects on the liability of developing pre-eclampsia and gestational hypertension, we cross-linked the population-based Swedish Twin Register and the Swedish Medical Birth Register. We included female twin pairs with known zygosity, both of whom gave birth in Sweden from 1973 through 1993; in all 917 monozygotic and 1,199 dizygotic twin pairs. For pre-eclampsia, the estimates of heritability and nonshared environmental effect were 0. 54 (95% confidence interval 0-0.71) and 0.46 (0.29-0.67), respectively; corresponding estimates for gestational hypertension were 0.24 (0-0.53) and 0.76 (0.47-1.00), respectively. When considering both diseases as a single entity (pregnancy-induced hypertensive diseases), the heritability estimate was 0.47 (0.13-0. 61). These results suggest that genetic factors are important in the development of pre-eclampsia as well as gestational hypertension. The heritability estimates can be of importance when planning genetic linkage studies. In efforts to identify women with elevated risk of developing pre-eclampsia during pregnancy, a question about family history of pre-eclampsia should be included.

Adolescent↗
PubMed2000

History of breast-feeding in relation to breast cancer risk: a review of the epidemiologic literature.

The purpose of this review is to critically evaluate the collective epidemiologic evidence that a history of breast-feeding may decrease the risk of breast cancer. Original data for inclusion were identified through a MEDLINE(R) search of the English language literature from 1966 through 1998. To date, virtually all epidemiologic data regarding breast-feeding and breast cancer risk are derived from case-control studies, which vary according to classification of breast-feeding history. Overall, the evidence with respect to "ever" breast-feeding remains inconclusive, with results indicating either no association or a rather weak protective effect against breast cancer. An inverse association between increasing cumulative duration of breast-feeding and breast cancer risk among parous women has been reported in some, but not all, studies; the failure to detect an association in some Western populations may be due to the low prevalence of prolonged breast-feeding. It appears that the protective effect, if any, of long-term breast-feeding is stronger among, or confined to, premenopausal women. It has been hypothesized that an apparently protective effect of breast-feeding may be due to elevated breast cancer risk among women who discontinue breast-feeding or who take medication to suppress lactation; however, the evidence is limited and should be interpreted with caution. The biology underlying a protective effect of breast-feeding and why this should be restricted to premenopausal women remain unknown, although several mechanisms have been postulated (hormonal changes, such as reduced estrogen; removal of estrogens through breast fluid; excretion of carcinogens from breast tissue through breast-feeding; physical changes in the mammary epithelial cells, reflecting maximal differentiation; and delay of the re-establishment of ovulation). While breast-feeding is a potentially modifiable behavior, the practical implication of reduced breast cancer risk among premenopausal women with prolonged durations of breast-feeding may be of marginal importance, particularly in Western societies.

Breast Feeding↗