Nutrition & Food Science
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Item HYPERLEPTINEMIA, METABOLIC SYNDROME, AND MORTALITY IN OLDER ADULTS(2010) Mishra, Suruchi; Sahyoun, Nadine R; Mehta, Mira; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Background: Abdominal adiposity and fat mass increase with aging, and as does insulin resistance which is frequently associated with hyperleptinemia and leptin resistance. Serum leptin may predict risk of metabolic syndrome and mortality among older adults. Objectives: The objectives of the present study were to evaluate the relationship of serum leptin with risk of metabolic syndrome and mortality and to examine these associations in relation to the measures of body adiposity and proinflammatory cytokines. The influence of leptin receptor (I/D) gene polymorphism on diabetes as a contributing cause of mortality was also examined. Gender specific serum leptin cut off values as a biomarker for the risk of metabolic syndrome were determined. Design: The Health, Aging and Body Composition (HABC) study is a prospective cohort of 3,075 older adults aged 70 to 79 years. Body composition, demographic information, biochemical variables including, markers of systemic inflammation, and genetic variation were assessed in detail. Results: Women in quintile 2, 3, 4 and 5 of serum leptin were at significantly lower risk for metabolic syndrome as compared to those in quintile 1 after controlling for confounders. Serum leptin was independently associated with risk of metabolic syndrome after sequentially adjusting for demographic variables (p<0.0001), fat depots (p=.0024), and proinflammatory cytokines (p=.0098) in women. Among men, the association between serum leptin and risk of metabolic syndrome was explained by body adiposity. Women in quartile 2 and 3 of serum leptin were at lower risk than women in quintile 1 for all-cause mortality and mortality from cardiovascular disease independent of body fat and proinflammatory cytokines. Additionally, elevated level of serum leptin was associated with increased risk for diabetes as a contributing cause of mortality for both genders after sequentially adjusting for potential confounders, body fat and proinflammatory cytokines. Significant interaction was found between leptin receptor genotype and total percent fat (p=0.008) in association with diabetes as a contributing cause of mortality among women. The cut off serum leptin level that suggests the possible risk of metabolic syndrome was determined to be 6.45 ng/ml with 60% sensitivity and 63% specificity among men and 18.25 ng/ml with 55% sensitivity and 62% specificity among women. Conclusion: Elevated levels of serum leptin may be associated with increased risk of metabolic syndrome and risk of diabetes as a contributing cause of mortality among older women. However, intermediary levels of serum leptin may lower the risk of all-cause mortality and mortality from CVD, suggesting a paradoxical association of serum leptin with cardiovascular risk factors and mortality from CVD among older womenItem Appropriate Waist Circumference Cutoff Values for the Diagnosis of Metabolic Syndrome in Mexican American Adults(2009) Sarafrazi, Neda; Jackson, Robert T; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Metabolic syndrome increases the risk of cardiovascular disease and diabetes. The International Diabetes Federation (IDF) recently proposed new criteria for the diagnosis of metabolic syndrome, which requires the presence of central obesity as measured by ethnic specific waist circumference (WC) cutoff values. Currently, no specific WC thresholds for diagnosis of central obesity in Hispanics are available. The objectives were to determine the appropriate gender specific WC thresholds for diagnosis of central obesity in Mexican American adults and to estimate the prevalence of metabolic syndrome using IDF definition with and without the modified WC in this population. Data from 3265 Mexican American adults aged 20-80 years who participated in the National Health and Nutrition Examination Survey 1999-2006 were used. The prevalence of metabolic syndrome was compared using IDF criteria with and without the modified waist circumference. Receiver operating characteristic curve analysis suggested that yielding at least 80% sensitivity, the WC value of 90 cm in both genders was more appropriate in predicting the presence of two or more metabolic syndrome risk factors in this population. Based on this cutoff, there was 34% reduction in the prevalence of central obesity in women (82.5% to 54.2%). The age adjusted prevalence of metabolic syndrome decreased from 58.4 to 48.2%. The metabolic syndrome was more common among Mexican American men than women (55.8% in men versus 37.8% in women, P =0.0003). Our findings provided a practical guidance in the assessment and screening of central obesity and metabolic syndrome in Mexican Americans.Item Supplementation strategy and its impact on hematological status in the control of anemia of pregnancy in Senegal(2007-07-31) Seck, Binetou Cheikh; Jackson, Robert T; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Anemia of pregnancy remains highly prevalent in Senegal despite the national iron/folic acid (IFA) supplementation program, which consists of providing prescriptions to purchase IFA to women during prenatal visits. The purpose of this study was to provide a framework for recommendations to improve the effectiveness of the program. We determined the prevalence and risk factors of anemia in a cohort of 480 pregnant women at 6 prenatal health centers in Dakar; we compared compliance after 20 weeks of supplementation between women who received prescriptions at 3 control centers and those who received free IFA at 3 intervention centers; and we assessed the factors that influenced high and low compliance in both groups. Overall, 39% of women were anemic and 71% were iron deficient (ID). Twelve percent were infected with P. falciparum; 21% had intestinal helminthes, and 6.5% had Hb AS. Women consumed foods containing iron absorption inhibitors at high frequency. ID > quadrupled the risk of anemia; malaria and Hb AS also significantly increased the risk for anemia. Compliance was 48% and 86% in the control and intervention groups, respectively (P<.001). Anemia prevalence was 62% among controls versus 31% among interventions (P<.01); ID prevalence was 84% and 57% in the control and intervention groups, respectively (P<.01). Women with high compliance were motivated by 1) the perception of improved health upon taking the tablets, 2) the insistence by midwives that they take them, and 3) the mention that the tablets would improve health. Women with low compliance indicated 1) experiencing side effects that they associated with the tablets, 2) misunderstanding that they needed to continue taking the tablets throughout pregnancy, and 3) forgetfulness. Our findings indicate that for effective control of anemia in Senegal, iron supplementation is needed in addition to educating women about better food choices. Antimalarial chemoprophylaxis and helminthes screening should be made available to all women. In addition, increasing access to IFA and educating women about the health benefits of the tablets can dramatically increase compliance and therefore improve iron status and decrease the incidence of anemia.Item The Relationship of Low Birth Weight and Current Obesity to Diabetes in African-American Women(2007-04-26) Harris, B. Michelle; Lei, David K. Y.; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Aims: (1) To test the fetal origins of chronic disease by examining birth weight, current obesity, and odds of developing type 2 diabetes (T2DM) in African-American women 38-57 years. (2) To assess birth weight and obesity in relation to fasting plasma glucose (FPG). Background: African-American women suffer disproportionately in prevalence and complications of T2DM. According to the fetal origins of chronic disease, T2DM is related to low birth weight with subsequent adult obesity. Several studies have substantiated this hypothesis; none have focused on African-American women. Outcome Measure: Self-reported physician diagnosis of T2DM. Exposure Measures: Birth weight, an indicator for fetal growth; waist-to-hip ratio, a marker for abdominal obesity. Other factors: physical activity, body mass index (BMI), history of gestational diabetes, blood pressure. Design: Retrospective, case-control observational study. Method: Convenience sample of urban African-American women. Cases (n=95) reported a physician diagnosis of T2DM. Controls (n=186), matched on race and age, reported no T2DM diagnosis. To verify control status, participants were screened for elevated FPG (cut-point, <126>mg/dL, as defined by the American Diabetes Association). Vital and family records were sources for birth weight. Current weight, height, and waist and hip circumferences were measured; BMI and waist-to-hip ratio were calculated. Confounding factors were collected on a 68-item questionnaire. Logistic regression analysis tested the proposed model for the odds of having T2DM. Multiple linear regression analysis was employed to assess FPG. Sample size was estimated. Results: The odds ratio for T2DM increased as waist-to-hip ratio increased (OR=1.13, 95% CI=1.08, 1.19, p<.0001). Birth weight did not contribute independently to the model's ability to examine T2DM (OR=0.92, 95% CI=0.74, 1.14, p=.4409). Birth weight and waist-to-hip ratio each contributed independently to assessing FPG. Conclusions: This study found an interaction between birth weight and abdominal obesity when examining T2DM in African-American women: those born small and who subsequently developed abdominal obesity had a greater odds for T2DM. Abdominal obesity, but not birth weight, was independently associated with T2DM. FPG significantly increased with increasing abdominal obesity and decreasing birth weight. African-American women are cautioned to maintain healthy body measures (waist-to-hip ratio <0.80 and BMI <25) to address T2DM.