Biomedical subjects

David R Jacobs

Publications and source records attributed to David R Jacobs.

At least 55 records · Page 3Linked to original sources

PubMed2006

Common presence of non-transferrin-bound iron among patients with type 2 diabetes.

OBJECTIVE: Recently, we reported increased cardiovascular disease mortality among supplemental vitamin C users with type 2 diabetes in a prospective cohort study. Because vitamin C may cause oxidative stress in the presence of redox active iron, we hypothesized that non-transferrin-bound iron (NTBI), a form of iron susceptible to redox activity, may be present in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: We measured serum NTBI levels using high-performance liquid chromatography in 48 patients with known diabetes (at least 5 years duration since diagnosis), 49 patients with newly diagnosed diabetes, and 47 healthy control subjects (frequency matched on age and sex). RESULTS: NTBI was commonly present in diabetes: 59% in newly diagnosed diabetes and 92% in advanced diabetes. Mean NTBI values varied significantly between the three groups, with the highest values being observed in patients with known diabetes and the lowest in the control subjects (0.62 +/- 0.43 vs. 0.24 +/- 0.29 vs. 0.04 +/- 0.13 micromol/l Fe). Serum total iron or percent transferrin saturation were very similar among the three groups, yet NTBI was strongly associated with serum total iron (r = 0.74, P < 0.01) and percent transferrin saturation (r = 0.70, P < 0.01) among the patients with known diabetes. CONCLUSIONS: Consistent with our hypothesis, these data demonstrate the common existence of NTBI in type 2 diabetic patients with a strong gradient with severity. Prospective cohort studies are required to clarify the clinical relevance of increased NTBI levels.

C-Reactive Protein↗

PubMed2006

Are your patients with risk of CVD getting the viscous soluble fiber they need?

A diet that includes 5 to 10 g/d of viscous soluble fiber reduces cardiovascular disease (CVD) events and death independent of baseline risk. Consuming foods rich in viscous soluble fiber reduces low-density lipoprotein cholesterol (LDL-C) blood levels 10% to 15% with expected reduction in CVD events by 10% to 15%. Routinely counsel adults at risk of CVD to promote a healthy diet: assess dietary fiber consumption; recommend specific foods rich in viscous soluble fiber; monitor LDL-C levels and encourage increased dietary fiber intake at follow-up visits; motivate patients to comply with recommendations.

Adult↗

PubMed2005

Nut and seed consumption and inflammatory markers in the multi-ethnic study of atherosclerosis.

Nuts and seeds are rich in unsaturated fat and other nutrients that may reduce inflammation. Frequent nut consumption is associated with lower risk of cardiovascular disease and type 2 diabetes. The authors examined associations between nut and seed consumption and C-reactive protein, interleukin-6, and fibrinogen in the Multi-Ethnic Study of Atherosclerosis. This 2000 cross-sectional analysis included 6,080 US participants aged 45-84 years with adequate information on diet and biomarkers. Nut and seed consumption was categorized as never/rare, less than once/week, 1-4 times/week, and five or more times/week. After adjustment for age, gender, race/ethnicity, site, education, income, smoking, physical activity, use of fish oil supplements, and other dietary factors, mean biomarker levels in categories of increasing consumption were as follows: C-reactive protein-1.98, 1.97, 1.80, and 1.72 mg/liter; interleukin-6-1.25, 1.24, 1.21, and 1.15 pg/ml; and fibrinogen-343, 338, 338, and 331 mg/dl (all p's for trend < 0.01). Further adjustment for hypertension, diabetes, medication use, and lipid levels yielded similar results. Additional adjustment for body mass index moderately attenuated the magnitude of the associations, yielding borderline statistical significance. Associations of nut and seed consumption with these biomarkers were not modified by body mass index, waist:hip ratio, or race/ethnicity. Frequent nut and seed consumption was associated with lower levels of inflammatory markers, which may partially explain the inverse association of nut consumption with cardiovascular disease and diabetes risk.

Aged↗

PubMed2005

Dietary fiber intake and risk of colorectal cancer: a pooled analysis of prospective cohort studies.

CONTEXT: Inconsistent findings from observational studies have continued the controversy over the effects of dietary fiber on colorectal cancer. OBJECTIVE: To evaluate the association between dietary fiber intake and risk of colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS: From 13 prospective cohort studies included in the Pooling Project of Prospective Studies of Diet and Cancer, 725,628 men and women were followed up for 6 to 20 years across studies. Study- and sex-specific relative risks (RRs) were estimated with the Cox proportional hazards model and were subsequently pooled using a random-effects model. MAIN OUTCOME MEASURE: Incident colorectal cancer. RESULTS: During 6 to 20 years of follow-up across studies, 8081 colorectal cancer cases were identified. For comparison of the highest vs lowest study- and sex-specific quintile of dietary fiber intake, a significant inverse association was found in the age-adjusted model (pooled RR = 0.84; 95% confidence interval [CI], 0.77-0.92). However, the association was attenuated and no longer statistically significant after adjusting for other risk factors (pooled multivariate RR = 0.94; 95% CI, 0.86-1.03). In categorical analyses compared with dietary fiber intake of 10 to <15 g/d, the pooled multivariate RR was 1.18 (95% CI, 1.05-1.31) for less than 10 g/d (11% of the overall study population); and RR, 1.00 (95% CI, 0.85-1.17) for 30 or more g/d. Fiber intake from cereals, fruits, and vegetables was not associated with risk of colorectal cancer. The pooled multivariate RRs comparing the highest vs lowest study- and sex-specific quintile of dietary fiber intake were 1.00 (95% CI, 0.90-1.11) for colon cancer and 0.85 (95% CI, 0.72-1.01) for rectal cancer (P for common effects by tumor site = .07). CONCLUSIONS: In this large pooled analysis, dietary fiber intake was inversely associated with risk of colorectal cancer in age-adjusted analyses. However, after accounting for other dietary risk factors, high dietary fiber intake was not associated with a reduced risk of colorectal cancer.

Colorectal Neoplasms↗

PubMed2005

Twenty-year trends in serum cholesterol, hypercholesterolemia, and cholesterol medication use: the Minnesota Heart Survey, 1980-1982 to 2000-2002.

BACKGROUND: Although US cholesterol concentrations have dropped, &50% of adults have total cholesterol concentrations > or =5.18 mmol/L, putting them at "borderline-high risk" for heart disease. Whether the decline has continued into the 21st century is unknown. We assessed 20-year trends in cholesterol, hypercholesterolemia, lipid-lowering drug use, and cholesterol awareness, treatment, and control from Minnesota Heart Survey (MHS) data. METHODS AND RESULTS: Five independent, cross-sectional, population-based surveys of 2500 to 5000 adults were conducted in the Minneapolis-St. Paul, Minn, area from 1980 to 2002. Mean (nonfasting) total cholesterol concentrations have continued a 20-year decline, punctuated by an intervening lull. Age-adjusted mean total cholesterol concentrations in 2000 to 2002 were 5.16 and 5.09 mmol/L for men and women, respectively (in 1980 to 1982, 5.49 and 5.38 mmol/L for men and women, respectively) However, the decline has not been uniform across all age groups. Middle-aged to older people have shown substantial decreases, but younger people have shown little overall change and recently had increased total cholesterol values. The mean prevalence of hypercholesterolemia in 2000 to 2002 was 54.9% for men and 46.5% for women and has decreased significantly for both during the study. Age-adjusted mean high-density lipoprotein cholesterol concentrations in 2000 to 2002 were 1.09 and 1.40 mmol/L for men and women, respectively, and were not different from the prior survey. Lipid-lowering drug use rose significantly for both sexes aged 35 to 74 years. Awareness, treatment, and control of hypercholesterolemia have increased; however, more than half of those at borderline-high risk remain unaware of their condition. CONCLUSIONS: Although hypercholesterolemia prevalence continued to fall, significant population segments still have cholesterol concentrations near or at the level of increased risk.

Adult↗

PubMed2005

Socioeconomic differences in progression of carotid intima-media thickness in the Atherosclerosis Risk in Communities study.

OBJECTIVE: To examine the association of socioeconomic factors with progression of carotid intimal-medial thickness (IMT) in middle-aged adults. Cross-sectional associations of IMT with socioeconomic status (SES) have been demonstrated in middle-aged cohorts. It is unclear whether these factors are associated with progression of IMT. METHODS AND RESULTS: We examined IMT progression over 9 years among a middle-aged cohort of 12,085 black and white subjects free of cardiovascular disease recruited from 4 US sites participating in the Atherosclerosis Risk in Communities (ARIC) study. Baseline IMT was inversely related to SES among whites and blacks. Repeated measures regression models of IMT progression showed moderate inverse relationships of IMT progression with income in whites so that the difference in 5-year IMT progression rates between the highest and lowest categories was -11.5 microm (CI, -17.4 to -5.6). In contrast, among blacks, this gradient is reversed, with an 11.1 microm (CI, -0.1 to 22.3) difference in 5-year progression between highest and lowest income category. Generally, similar patterns were observed for other socioeconomic indicators. Patterns were not accounted for by baseline cardiovascular risk factors. CONCLUSIONS: SES is inversely related to IMT progression in middle-aged whites but positively related to IMT progression among middle-aged blacks. These differences do not appear to be attributable to selective attrition or higher IMT among blacks at baseline.

Black People↗

PubMed2005

Heme iron, zinc and upper digestive tract cancer: the Iowa Women's Health Study.

We examined associations among dietary heme iron as a possible pro-oxidant, dietary zinc as a possible antioxidant, and the incidence of upper digestive tract cancer; 34,708 postmenopausal women, aged 55-69 years at baseline who completed a food frequency questionnaire, were followed 16 years. There were 75 upper digestive tract cancer cases (52 gastric cancer and 23 esophageal cancer). When heme iron and zinc were mutually adjusted, in dose-response manners, heme iron intake was positively associated with the risk of upper digestive tract cancer, while zinc intake was inversely associated with risk. After adjusting for age, total energy intake, cigarette smoking and alcohol consumption, relative risks for quintiles of heme iron intake were 1.0, 1.53, 2.15, 3.05 and 2.83 (p for trend = 0.06) and corresponding relative risks for zinc intake were 1.0, 0.86, 0.42, 0.37 and 0.13 (p for trend < 0.01). Additional adjustment for body mass index, physical activity, hormone replacement therapy, multivitamin intake and intake of saturated fat, vitamin C, vitamin E and folate did not change the results. Higher intake of heme iron is associated with higher risk, while higher intake of zinc is associated with lower, risk of upper digestive tract cancer.

Aged↗

PubMed2005

A strong secular trend in serum gamma-glutamyltransferase from 1996 to 2003 among South Korean men.

Serum gamma-glutamyltransferase (GGT) concentration, within its normal range, has recently been proposed as a reliable marker of oxidative stress. Oxidative stress plays a central pathogenic role in many metabolic and/or cardiovascular diseases, incidences of which have recently increased in South Korea. Since serum GGT has strong associations with these diseases and their risk factors, the authors hypothesized a corresponding secular trend of increasing serum GGT levels in South Korea. Study subjects were 8,072 male workers at a large steel company who were aged 24-44 years at baseline and had received annual physical examinations from 1996 to 2003. The secular trend was a 0.1066-units/liter increase in ln(GGT) level per calendar year (a 180% increase during the 7-year follow-up period) (p < 0.01). Adjustment for body mass index, alcohol consumption, smoking, exercise, and cholesterol level as time-dependent covariates did not change the results. Although cholesterol is commonly used as a marker of epidemiologic transition, there was a less dramatic secular trend in ln(serum cholesterol) level, and it disappeared after adjustment for the secular trend in serum GGT. These findings suggest that serum GGT concentration can be used as a sensitive marker of epidemiologic transition, and they portend a continuing rise in incidences of metabolic and/or cardiovascular diseases in this population in the coming years.

Adult↗

PubMed2005

Acculturation and socioeconomic position as predictors of coronary calcification in a multiethnic sample.

BACKGROUND: Coronary calcium has recently emerged as a marker of subclinical coronary heart disease. Although there has been much interest in race differences in calcification, heterogeneity within race or ethnic groups has not been investigated. METHODS AND RESULTS: Data from the Multi-Ethnic Study of Atherosclerosis (MESA), a population-based study of coronary calcification, were used to investigate acculturation and socioeconomic position as predictors of coronary calcification within 2553 non-Hispanic whites, 1734 non-Hispanic blacks, 1457 Hispanics, and 797 Chinese residing in the United States. Coronary calcium was assessed by chest CT. Relative risk regression and linear regression were used to estimate adjusted associations of sociodemographic variables with the presence and amount of calcium. Not being born in the United States was associated with a lower prevalence of calcification in blacks (relative prevalence [RP], 0.75; 95% confidence limit [CL], 0.61 to 0.94) and Hispanics (RP, 0.89; 95% CL, 0.81 to 0.98) after adjustment for age, sex, income, and education. Years in the United States was positively associated with prevalence of calcification in non-US-born Chinese (adjusted RP per 10 years in United States, 1.06; 95% CL, 1.01 to 1.11) and non-US-born blacks (RP, 1.59; 95% CL, 1.22 to 2.06). Low education was associated with a higher prevalence of calcification in whites (adjusted RP for no high school versus complete college, 1.17; 95% CL, 1.05 to 1.32) but with lower prevalence of calcification in Hispanics (RP, 0.91; 95% CL, 0.77 to 1.09) (P for interaction=0.02). US birth and time in the United States were also positively associated with the extent of calcification in persons with detectable calcium. These differences did not appear to be accounted for by smoking, body mass index, LDL and HDL cholesterol, hypertension, and diabetes. CONCLUSIONS: Acculturation and socioeconomic factors are associated with differences in the prevalence and amount of coronary calcification within whites, Chinese, blacks, and Hispanics. The presence of this heterogeneity needs to be acknowledged in the quantification and investigation of race/ethnic differences.

Acculturation↗

PubMed2005

Urine albumin excretion and subclinical cardiovascular disease. The Multi-Ethnic Study of Atherosclerosis.

We examined the association between urine albumin excretion (UAE) and common and internal carotid artery intima-media thickness (IMT), end-diastolic left ventricular (LV) mass, and coronary artery calcification (CAC) scores using data from the Multi-Ethnic Study of Atherosclerosis (MESA), a population-based study of 6814 adults aged 45 to 85 years without clinical cardiovascular disease (CVD). The mean age of the MESA participants was 62.7 years, 47% were male, and 15% had diabetes mellitus (DM). Sex-specific spot urine albumin/creatinine ratios were used to define 4 UAE categories: normal, high normal, microalbuminuria, and macroalbuminuria. CAC scores were log-transformed after adding 1 to all scores. Mean values of subclinical CVD measures were computed by level of UAE after adjustment for blood pressure, DM, and other covariates. After adjustment for all covariates, geometric mean CAC scores were higher among participants with high normal UAE (8.8; P=0.07), microalbuminuria (9.9; P=0.002), and macroalbuminuria (13.1; P=0.02) compared with normal UAE (7.4), but only microalbuminuria reached statistical significance. Mean LV mass (g/m2.7) was significantly higher in participants with high normal UAE (37.0; P=0.001), microalbuminuria (38.3; P< or =0.0001), and macroalbuminuria (42.3; P< or =0.0001) compared with normal UAE (36.0) after adjustment for all covariates. No significant difference in mean carotid IMT was found after adjustment for all covariates. Similar results were noted in MESA participants with and without DM. In conclusion, higher UAE, including levels below microalbuminuria, may reflect the presence of subclinical CVD among adults without established CVD.

Aged↗

PubMed2005

The uncoupling protein 2 Ala55Val polymorphism is associated with diabetes mellitus: the CARDIA study.

BACKGROUND: Uncoupling proteins (UCPs) reduce ATP generation with concomitant increased release of heat. The activities of UCPs have been related to obesity and energy metabolism. METHODS: We investigated the association of the commonly observed UCP2 Ala55Val (V) polymorphism with diabetes mellitus and impaired fasting glucose (IFG) among 3684 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study. RESULTS: The V frequency was approximately 45% in blacks and 42% in whites. Those with the Val/Val (VV) genotype had a higher incidence of diabetes than those having the Ala/Ala (AA) genotype (5.8% vs 3.3%; P = 0.02). Similarly, the incidences of diabetes in participants without abdominal obesity were 2.8% and 1.0% (P = 0.03) in the VV and AA groups, and 12.4% and 8.3% (P = 0.15) in participants with abdominal obesity. The incidence of IFG was higher in VV vs AA only in those without abdominal obesity (12.9% vs 9.2%). These trends persisted in minimally and fully adjusted models, and in strata of blacks and whites and men and women. The homeostasis model assessment for insulin resistance was highest in VV in the combined group of those with IFG or untreated diabetes, but not in those with normal fasting glucose. CONCLUSION: The VV genotype of the UCP2 polymorphism was positively related to diabetes. It may involve increased insulin resistance in those with impaired glucose homeostasis.

Adult↗

PubMed2005

Serum gamma-glutamyltransferase was differently associated with microalbuminuria by status of hypertension or diabetes: the Coronary Artery Risk Development in Young Adults (CARDIA) Study.

BACKGROUND: We hypothesized that serum gamma-glutamyltransferase (GGT) would positively predict the risk of microalbuminuria, a frequent consequence of both diabetes and hypertension, because serum GGT predicted diabetes and hypertension in dose-response relationships. METHODS: In this prospective study, 2478 black and white men and women without microalbuminuria at year 10 provided urine samples 5 years later. Year 10 GGT cutpoints were 12, 18, and 29 U/L. RESULTS: The incidence of microalbuminuria across year 10 GGT categories was U-shaped. Adjusted odds ratios across quartiles of serum GGT were 1.0, 0.39, 0.54, and 0.94 (P <0.01 for quadratic term), but the shape of association depended on the status of hypertension or diabetes (P <0.01 for interaction). Among individuals who ever had hypertension or diabetes, year 10 serum GGT showed a clear positive dose-response association with incident microalbuminuria (P <0.01 for trend), whereas among individuals with neither hypertension nor diabetes during the study, year 10 GGT showed a U-shaped association with it (P = 0.01 for quadratic term). When the long-term risk was evaluated in 3895 participants based on serum GGT at year 0 and prevalence of microalbuminuria at year 10 or year 15, the trends were similar but weaker than those of short-term incidence risk. CONCLUSIONS: Serum GGT within the physiologic range predicted microalbuminuria among patients with hypertension or diabetes and may act as a predictor of microvascular and/or renal complications in these vulnerable groups. GGT showed a U-shaped association with microalbuminuria among persons who did not develop either hypertension or diabetes.

Adolescent↗

PubMed2005

Relation of body mass index and insulin resistance to cardiovascular risk factors, inflammatory factors, and oxidative stress during adolescence.

BACKGROUND: This study assessed the relation of fatness and insulin resistance and their interaction with cardiovascular risk factors, inflammatory factors, and oxidative stress in thin and heavy adolescents. METHODS AND RESULTS: Euglycemic insulin clamp studies were performed on 295 (169 male, 126 female) adolescents (mean+/-SE age, 15+/-0.1 years). Comparisons were made between (1) heavy and thin adolescents; (2) insulin-sensitive and insulin-resistant adolescents; and (3) thin insulin-sensitive (T-IS), thin insulin-resistant (T-IR), heavy insulin-sensitive (H-IS), and heavy insulin-resistant (H-IR) adolescents. Summed z scores were used to determine clustering of risk factors (fasting insulin, triglycerides, HDL-C, and systolic blood pressure [SBP]) among the groups. SBP, triglycerides, and fasting insulin were significantly higher and HDL-C significantly lower in the heavy adolescents. Fasting insulin and triglycerides were significantly higher and HDL-C significantly lower in the insulin-resistant adolescents. Among the 4 groups, the risk factors and cluster score followed a pattern of risk as follows: T-IS<T-IR<H-IS<H-IR, with H-IR significantly greater than the other groups and showing an interaction between fatness and insulin resistance. CONCLUSIONS: These results show the significant association of both fatness and insulin resistance and their significant interaction with cardiovascular risk factors in adolescence. The finding that insulin resistance may be acting interactively with fatness suggests that interventions directed at insulin resistance in addition to weight loss may be required to alter early development of cardiovascular risk.

Adolescent↗

PubMed2005

Eliminating diagnostic drift in the validation of acute in-hospital myocardial infarction--implication for documenting trends across 25 years: the Minnesota Heart Survey.

Long-term trends in epidemiologic studies of acute myocardial infarction (AMI) require application of a consistent diagnostic algorithm. Typically an algorithm includes chest pain, cardiac enzymes, electrocardiographic findings, and autopsy results. The Minnesota Heart Survey (MHS) has determined trends for incident AMI and for in-hospital and long-term outcomes over a 25-year period (1970-1995). However, dramatic changes have occurred that seriously challenge the ability of the MHS and other epidemiologic studies to use a consistent diagnostic algorithm. These include newer and more sensitive cardiac biomarkers, introduction of diagnosis-related groups, and change in International Classification of Diseases coding. In the MHS, the electrocardiogram is the only diagnostic element consistently available and consistently classified over this 25-year period. The authors identified eight dichotomous Minnesota Code criteria that provided a consistent diagnostic method from 1970 to 1995 as documented by extensive cross-validation. These criteria were combined into a logistic score and used to define incident, recurrent, and attack AMI rates over this 25-year period. For both men and women, AMI rates determined by electrocardiogram are parallel to rates based on the International Classification of Diseases and parallel over adjacent survey periods to the standard MHS algorithm. The electrocardiogram classified by Minnesota Code provides the only consistent long-term diagnostic tool for AMI trends over this 25-year period.

Adult↗

PubMed2005

Periodontal microbiota and carotid intima-media thickness: the Oral Infections and Vascular Disease Epidemiology Study (INVEST).

BACKGROUND: Chronic infections, including periodontal infections, may predispose to cardiovascular disease. We investigated the relationship between periodontal microbiota and subclinical atherosclerosis. METHODS AND RESULTS: Of 1056 persons (age 69+/-9 years) with no history of stroke or myocardial infarction enrolled in the Oral Infections and Vascular Disease Epidemiology Study (INVEST), we analyzed 657 dentate subjects. Among these subjects, 4561 subgingival plaque samples were collected (average of 7 samples/subject) and quantitatively assessed for 11 known periodontal bacteria by DNA-DNA checkerboard hybridization. Extensive in-person cardiovascular risk factor measurements, a carotid scan with high-resolution B-mode ultrasound, white blood cell count, and C-reactive protein values were obtained. In 3 separate analyses, mean carotid artery intima-media thickness (IMT) was regressed on tertiles of (1) burden of all bacteria assessed, (2) burden of bacteria causative of periodontal disease (etiologic bacterial burden), and (3) the relative predominance of causative/over other bacteria in the subgingival plaque. All analyses were adjusted for age, race/ethnicity, gender, education, body mass index, smoking, diabetes, systolic blood pressure, and LDL and HDL cholesterol. Overall periodontal bacterial burden was related to carotid IMT. This relationship was specific to causative bacterial burden and the dominance of etiologic bacteria in the observed microbiological niche. Adjusted mean IMT values across tertiles of etiologic bacterial dominance were 0.84, 0.85, and 0.88 (P=0.002). Similarly, white blood cell values increased across tertiles of etiologic bacterial burden from 5.57 to 6.09 and 6.03 cells x10(9)/L (P=0.01). C-reactive protein values were unrelated to periodontal microbial status (P=0.82). CONCLUSIONS: Our data provide evidence of a direct relationship between periodontal microbiology and subclinical atherosclerosis. This relationship exists independent of C-reactive protein.

Aged↗

PubMed2005

Associations of dietary protein with disease and mortality in a prospective study of postmenopausal women.

Some weight loss diets promote protein intake; however, the association of protein with disease is unclear. In 1986, 29,017 postmenopausal Iowa women without cancer, coronary heart disease (CHD), or diabetes were followed prospectively for 15 years for cancer incidence and mortality from CHD, cancer, and all causes. Mailed questionnaires assessed dietary, lifestyle, and medical information. Nutrient density models estimated risk ratios from a simulated substitution of total and type of dietary protein for carbohydrate and of vegetable for animal protein. The authors identified 4,843 new cancers, 739 CHD deaths, 1,676 cancer deaths, and 3,978 total deaths. Among women in the highest intake quintile, CHD mortality decreased by 30% from an isoenergetic substitution of vegetable protein for carbohydrate (95% confidence interval (CI): 0.49, 0.99) and of vegetable for animal protein (95% CI: 0.51, 0.98), following multivariable adjustment. Although no association was observed with any outcome when animal protein was substituted for carbohydrate, CHD mortality was associated with red meats (risk ratio = 1.44, 95% CI: 1.06, 1.94) and dairy products (risk ratio = 1.41, 95% CI: 1.07, 1.86) when substituted for servings per 1,000 kcal (4.2 MJ) of carbohydrate foods. Long-term adherence to high-protein diets, without discrimination toward protein source, may have potentially adverse health consequences.

Aged↗

PubMed2005

Association between serum gamma-glutamyltransferase and C-reactive protein.

A series of epidemiological studies have suggested serum gamma glutamyltransferase (GGT) within its normal range might be an early marker of oxidative stress. Oxidative stress appears to be a key component of many reactions associated with chronic inflammation. Therefore, we examined the cross-sectional association between deciles of serum GGT and concentrations of serum C-reactive protein (CRP), a marker of chronic inflammation, among 12,110 adult participants in the third U.S. National Health and Nutrition Examination Survey. After adjustment for race, sex, age, cigarette smoking, alcohol intake, and body mass index (BMI), serum concentration of GGT across all deciles was positively associated with serum concentrations of CRP (P for trend<0.01). For example, adjusted relative risks of serum CRP> or =3.0mg/L by deciles of serum GGT were 1.0, 1.23, 1.40, 1.59, 1.62, 1.61, 2.17, 2.38, 2.45, and 3.41 (P for trend<0.01). This association was consistently observed among all subgroups; Non-Hispanic White, Non-Hispanic Black, Mexican American, men, women, non-drinkers, drinkers, non-smokers, ex-smokers, current smokers, BMI<25, BMI 25-29.9, and BMI> or =30. The strong association of serum GGT and CRP suggest that further studies on cellular and/or serum GGT might help to elucidate the association between oxidative stress and inflammation.

Aged↗

PubMed2005

Inverse effects of the PPAR(gamma)2 Pro12Ala polymorphism on measures of adiposity over 15 years in African Americans and whites. The CARDIA study.

Few studies have addressed the association of the Pro12Ala polymorphism of the peroxisome proliferator-activated receptor gamma 2 (PPAR gamma 2) gene with longitudinal measures of adiposity and insulin sensitivity during young adulthood, or reported on its relationship with these outcomes in African Americans. These issues were examined in the biracial Coronary Artery Risk Development in Young Adults (CARDIA) cohort, a population-based sample of 5115 African Americans and whites followed prospectively over 15 years. Frequency of the Ala12 allele was 2.1% in African Americans and 12.8% in whites, consistent with previous reports. A generalized estimating equation method was used to simultaneously examine the cross-sectional and longitudinal relationships between the Pro12Ala polymorphism and the measures of adiposity and insulin sensitivity. The Pro12Ala polymorphism was significantly associated with mean 15-year levels of adiposity, but these associations were in opposite direction in the 2 racial groups. On average, African Americans carrying the Ala12 allele had a 1.1 kg/m2 lower body mass index (BMI) ( P = .02) and whites a 0.6 kg/m2 higher BMI ( P = .01), as compared to Pro12 homozygotes. The Ala12 allele was also significantly associated with a decreased risk of incident insulin resistance syndrome in each race (OR = 0.44, P = .04 in African Americans; OR = 0.61, P = .01 in whites) and lower mean 15-year levels of fasting insulin ( P = .02), glucose ( P = .02), and homeostasis model assessment ( P = .01) in African Americans but not in whites. Important roles of BMI and ethnic background in influencing the complex relationships among PPAR gamma gene variation, adiposity, and insulin resistance are suggested.

Adipose Tissue↗