Developmental variations in plasma leptin, leptin soluble receptor and their molar ratio in healthy infants

<p>Abstract</p> <p>Background</p> <p>Leptin and its soluble receptor (sOB-R) are important to regulation of body composition but there are no data on the developmental variations in these plasma variables and their relationship with body composition measurements,</p> <p>Methods</p> <p>Weight, length, and body composition (bone, fat and lean mass) by dual energy absorptiometry, and plasma variables were measured in healthy infants at 2, 4, 8 and 12 months.</p> <p>Results</p> <p>15 whites and 29 African Americans (21 males and 23 females) with mean birth weight 3357 +/- 45 (SEM) g and gestation of 39.3 +/- 0.17 weeks were studied. The overall Z score for weight, length and weight for length during the study were 0.00 +/- 0.15, -0.08 +/- 0.11 and 0.12 +/- 0.14 respectively. With increasing age, plasma leptin (1.0 to 18.2, median 5.5 ng/mL) and sOB-R:leptin molar ratio (10.1 to 247.4, median 59.9) were lowered (r = -0.47, p < 0.01; and r = -0.37, p < 0.05 respectively), best predicted by weight Z score and percentage of fat mass, and higher in African American and female. Presence of body composition measurements eliminated the race and gender effect on the plasma variables. Plasma sOB-R (49.5 to 173.9, median 81.3 ng/mL) did not change significantly with age and was correlated and predicted only by body composition measurements.</p> <p>Conclusion</p> <p>In healthy growing infants, plasma leptin but not sOB-R decreases with age. Gender, race and anthropometric measurements are additional physiological determinants predictive of plasma leptin and the receptor:ligand ratio. However, body composition is the only variable that can predict plasma leptin and its soluble receptor and the receptor: ligand ratio; and body composition measurements eliminated the race and gender effect on these plasma variables.</p

Disproportionate alterations in body composition of large for gestational age neonates

Objective: The objective was to compare dual-energy x-ray absorptiometry– measured body composition between large (LGA) and appropriate (AGA) birth weight for gestational age neonates. Study design: LGA term infants (n = 47) with birth weights ?4000 g were compared with 47 gestational age-matched AGA infants; 11 LGA infants were born to mothers with gestational (9) or pregestational diabetes (2). Dual-energy x-ray absorptiometry scans were performed at 1.8 ± 1.0 days after birth. Results: Body weight and length were the dominant predictors of body composition in LGA and AGA neonates. However, LGA neonates had significantly (P &lt; .001, all comparisons) higher absolute amounts of total body fat, lean body mass, and bone mineral content and had significantly (P &lt; .001, all comparisons) higher proportions of total body fat and bone mineral content but lower lean body mass as a percent of body weight. The changes for total body fat and lean body mass as a percent of body weight were greatest (P &lt; .001) in LGA infants whose mothers had impaired glucose tolerance. Conclusion: LGA neonates have higher body fat and lower lean body mass than AGA infants. Impaired maternal glucose tolerance exaggerated these body composition changes

Depression, Stress, and Blood Pressure in Urban African-American Women

African-American women have disturbingly high rates of hypertension, exceeding those of African-American men and other ethnic groups. Reasons for these disparities are not understood. Depression, more common in women than men, has been linked to endothelial dysfunction, inflammation, metabolic and hematologic abnormalities, and increased sympathetic nervous system activity--all factors associated with cardiovascular disease. A descriptive correlational design was used to test the following hypotheses: 1) African-American women with higher levels of depression will have higher blood pressure (BP) levels, more cardiovascular risk factors, greater stress, and lower social support; and 2) depression will mediate the relationship between stress and BP. A convenience sample of 245 hypertensive African-American women (mean age, 61+/-12.7 years) was recruited through free BP screenings offered in the community. All data were collected during a structured interview and brief physical examination. Pearson r correlation coefficients, analysis of variance, and multiple regression analyses were used to analyze the hypotheses. Women with higher levels of depression had higher diastolic BP and were more likely to smoke, eat fewer fruits and vegetables, and have more stress and less social support. Depression mediated the relationship between stress and diastolic BP. The findings emphasize the importance of assessing both behavioral and psychosocial factors in urban African-American women with hypertension

Body composition in neonates: relationship between measured and derived anthropometry with dual-energy X-ray absorptiometry measurements

This study examined the relationship between measured and derived anthropometric measurements with dual-energy x-ray absorptiometry measured lean and fat mass at 3.0 ± 2.8 (SD) days in 120 neonates with birth weights appropriate (AGA; n = 74), large (LGA; n = 30); or small (SGA, n = 16) for gestational age. Anthropometric measurements, including total body weight and length, and regional measurements, including circumferences of head, chest, abdomen, midarm, and midthigh and dynamic skinfold thickness (15 and 60 s) at tricep, subscapular, suprailiac, and midthigh, were performed. Derived anthropometry included muscle and fat areas, and ratios were calculated from direct measurements. The skinfold thickness measurements between 15 and 60 s were highly correlated (r = 0.973–0.996, p &lt; 0.001 for all comparisons). Strong correlations existed within the four circumferences of trunk and extremities, the four skinfolds, and the ratios of weight to length and its higher powers. Weight and length accounted for &gt;97% of the variance of lean mass in AGA and SGA infants and 46% of the variance in LGA infants and for 80, 82, and 84% of the variance of fat mass in SGA, AGA, and LGA infants, respectively, whereas midarm:head circumference ratio and arm muscle and fat areas are the most important derived anthropometry in the prediction for body composition. They independently accounted for up to 16.5 and 10.2%, respectively, of the variance in body composition depending on the state of in utero growth. Thus, total body weight and length and some selected regional and derived anthropometry accounted for the vast majority of the variance of body composition