Serum leptin concentrations are not related to dietary patterns but are related to sex, age, body mass index, serum triacylglycerol, serum insulin, and plasma glucose in the US population

<p>Abstract</p> <p>Background</p> <p>Leptin is known to play a role in food intake regulation. The aim of this study was to investigate the relation between serum leptin concentrations and dietary patterns and demographic, lifestyle, and health factors in the US population.</p> <p>Methods</p> <p>Data from the third National Health and Nutrition Examination Survey, 1988–1994 were used to study the association between fasting serum leptin and dietary patterns, sex, race-ethnicity, smoking, age, energy and alcohol intakes, body mass index (BMI), plasma glucose, serum triacylglycerol, and serum insulin in 4009 individuals. Factor analysis was used to derive three principle factors and these were labeled as Vegetable, Fruit, and Lean Meat, Western, and Mixed dietary patterns.</p> <p>Results</p> <p>Serum leptin concentrations were significantly higher in Vegetable, Fruit, and Lean Meat (8.5 fg/L) and Mixed patterns (8.0 fg/L) compared to Western pattern (6.29 fg/L) (P < 0.0001). When analysis was adjusted for confounding variables, no significant association was observed between serum leptin and dietary patterns (P = 0.22). Multivariate adjusted serum leptin concentrations were significantly associated with sex (higher in women than in men; β = -1.052; P < 0.0001), age (direct relation, β = 0.006, P < 0.0001), BMI, (direct relation, β = 0.082, P < 0.0001), fasting plasma glucose (inverse relation, β = -0.024, P = 0.0146), serum triacylglycerol (direct relation, β = 0.034, P = 0.0022), and serum insulin (direct relation, β = 0.003, P < 0.0001) but not with race-ethnicity (P = 0.65), smoking (P = 0.20), energy intake (P = 0.42), and alcohol intake (P = 0.73).</p> <p>Conclusion</p> <p>In this study, serum leptin was not independently associated with dietary patterns. Sex, age, BMI, serum triacylglycerol, plasma glucose, and serum insulin are independent predictors of serum leptin concentrations.</p

Glycemic load is associated with HDL cholesterol but not with the other components and prevalence of metabolic syndrome in the third National Health and Nutrition Examination Survey, 1988–1994

<p>Abstract</p> <p>Background</p> <p>Carbohydrate quality and quantity may affect the risk for cardiovascular diseases (CVD) and type-2 diabetes mellitus. Glycemic load (GL) is a mathematical concept based on carbohydrate quality and quantity. GL is a product of glycemic index (GI) and the carbohydrate content of a food item divided by 100.</p> <p>Objective</p> <p>In this study, the association between GL and components and prevalence of metabolic syndrome was investigated in a representative sample survey of US residents utilizing the data reported in the third National Health and Nutrition Examination Survey (<it>n </it>= 5011).</p> <p>Methods</p> <p>Metabolic syndrome was defined according to the criteria established by the Adult Treatment Panel III. Multivariate-adjusted means for waist circumference, triacylglycerol, systolic and diastolic blood pressures, blood glucose, and HDL cholesterol were determined according to the energy-adjusted GL intake quartiles using regression models.</p> <p>Results</p> <p>In all subjects and in men, high GL was associated with low HDL-cholesterol concentrations in multivariate-adjusted analysis (<it>P </it>for trend < 0.01). However, no association was observed between GL and any of the individual components of metabolic syndrome in women. Also, no association was observed between energy-adjusted GL and prevalence of metabolic syndrome in both men (<it>P </it>for trend < 0.21) and women (<it>P </it>for trend < 0.09) in the multivariate-adjusted logistic regression analysis.</p> <p>Conclusion</p> <p>It is likely that the diets low in GL may mitigate the risk for CVD through HDL cholesterol.</p

Population prevalence, attributable risk, and attributable risk percentage for high methylmalonic acid concentrations in the post-folic acid fortification period in the US

<p>Abstract</p> <p>Background</p> <p>Serum methylmalonic acid (MMA) is regarded as a sensitive marker of vitamin B-12 status. Elevated circulating MMA is linked to neurological abnormalities. Contribution of age, supplement use, kidney dysfunction, and vitamin B-12 deficiency to high serum MMA in post-folic acid fortification period is unknown.</p> <p>Methods</p> <p>We investigated prevalence, population attributable risk (PAR), and PAR% for high MMA concentrations in the US. Data from 3 cross-sectional National Health and Nutrition Examination Surveys conducted in post-folic acid fortification period were used (<it>n </it>= 18569).</p> <p>Results</p> <p>Likelihood of having high serum MMA for white relative to black was 2.5 (<it>P </it>< 0.0001), ≥ 60 y old persons relative to < 60 y old persons was 4.0 (<it>P </it>< 0.0001), non-supplement users relative to supplement users was 1.8 (<it>P </it>< 0.0001), persons with serum creatinine ≥ 130 μmol/L relative to those with < 130 μmol/L was 12.6 (<it>P </it>< 0.0001), and persons with serum vitamin B-12 < 148 pmol/L relative to those with ≥ 148 pmol/L was 13.5 (<it>P </it>< 0.0001). PAR% for high MMA for old age, vitamin B-12 deficiency, kidney dysfunction, and non-supplement use were 40.5, 16.2, 13.3, and 11.8, respectively. By improving serum vitamin B-12 (≥ 148 pmol/L), prevalence of high MMA would be reduced by 16-18% regardless of kidney dysfunction.</p> <p>Conclusions</p> <p>Old age is the strongest determinant of PAR for high MMA. About 5 cases of high serum MMA/1000 people would be reduced if vitamin B-12 deficiency (< 148 pmol/L) is eliminated. Large portion of high MMA cases are not attributable to serum vitamin B-12. Thus, caution should be used in attributing high serum MMA to vitamin B-12 deficiency.</p

Population Reference Values for Serum Methylmalonic Acid Concentrations and Its Relationship with Age, Sex, Race-Ethnicity, Supplement Use, Kidney Function and Serum Vitamin B12 in the Post-Folic Acid Fortification Period

Serum methylmalonic acid (MMA) is elevated in vitamin B-12 deficiency and in kidney dysfunction. Population reference values for serum MMA concentrations in post-folic acid fortification period are lacking. Aims of this study were to report the population reference values for serum MMA and to evaluate the relation between serum MMA and sex, age, race-ethnicity, kidney dysfunction and vitamin B-12. We used data from three National Health and Nutrition Examination Surveys, 1999–2000, 2001–2002 and 2003–2004 conducted after folic acid fortification commenced (n = 18,569). Geometric mean MMA was ≈22.3% higher in non-Hispanic white compared to non-Hispanic black (141.2 vs. 115.5 nmol/L) and was ≈62.7% higher in &gt;70 years old persons compared to 21–30 years old persons (196.9 vs. 121.0 nmol/L). Median serum MMA was ≈28.5% higher in the 1st the quartile of serum vitamin B-12 than in the 4th quartile of serum vitamin B-12 and was ≈35.8% higher in the 4th quartile of serum creatinine than in the 1st quartile of serum creatinine. Multivariate-adjusted serum MMA concentration was significantly associated with race-ethnicity (p &lt; 0.001) and age (p &lt; 0.001) but not with sex (p = 0.057). In this large US population based study, serum MMA concentrations presented here reflect the post-folic acid fortification scenario. Serum MMA concentrations begin to rise at the age of 18–20 years and continue to rise afterwards. Age-related increase in serum MMA concentration is likely to be due to a concomitant decline in kidney function and vitamin B-12 status