Body composition in women of reproductive age and during pregnancy. Method comparisons and gestational changes

Body composition measurements can contribute to assessment of nutritional status, both for clinical use and for research purpose. During pregnancy, body composition measurement is complicated by decreased density of the fat-free mass (FFM). Body composition assessment during pregnancy can be valuable for studies in unbeneficial gestational weight gain (GWG), as a large weight gain during pregnancy is associated with complications. In addition, nutritional intake during pregnancy is hypothesized to affect the growing foetus, and some polyunsaturated fatty acids (PUFA) are important for foetal development. In these studies, body composition measurements by quantitative magnetic resonance (QMR) and bioelectrical impedance analysis (BIA) were respectively compared with air displacement plethysmography (ADP) in normal weight and obese non-pregnant women of reproductive age and during pregnancy. Nonpregnant women were analyzed in a cross-sectional study. Pregnant women were measured in each trimester, and ADP measurements were adjusted for changed FFM density. Also, effects of a dietary intervention study in normal weight women during pregnancy were analyzed, with focus on fish intake, serum phospholipid (s-) PUFAs (arachidonic acid, ARA; docosahexaenoic acid, DHA; eicosapentaenoic acid, EPA), and body composition changes. Additionally, effects of fish intake and meat intake in early pregnancy were analyzed, with focus on s-PUFAs, GWG, and body composition changes. In non-pregnant normal weight women, fat mass (FM) estimates by QMR and by BIA were biased 1 kg compared with ADP. In non-pregnant obese women, FM estimates by QMR and by BIA were underestimated 2 kg and 9 kg respectively, compared with ADP. Total body water estimates by BIA were larger compared with QMR estimates in both normal weight and obese non-pregnant women. Reported fish intake increased from the first trimester to the second and third, respectively, in the group of normal weight women that received the dietary intervention. In early pregnancy, reported fish intake correlated with s-DHA and s-EPA, and reported meat intake correlated with s-ARA. In addition, reported meat intake in early pregnancy correlated with the subsequent maternal FFM gain. GWG was 12 kg with 4 kg FM in normal weight women, and 9 kg with 2 kg FM in obese women. Crosssectional FM and FM changes measured by QMR and by pregnancy-adjusted ADP were similar in obese women during pregnancy. BIA underestimated FM in obese pregnant women, compared with pregnancyadjusted ADP. FM measured by QMR and FM changes measured by BIA yielded higher values than pregnancy-adjusted ADP in normal weight women during pregnancy. In conclusion, dietary counselling during pregnancy may help women to increase fish intake. FM measurements by QMR and by BIA were biased in non-pregnant normal weight and obese women. QMR and the BIA equipment used here would need validation against gold standard methods during pregnancy, but the results indicate that the present software specific BIA equipment is unsuitable for FM measurements during pregnancy

Body composition in the elderly: Reference values and bioelectrical impedance spectroscopy to predict total body skeletal muscle mass

BACKGROUND & AIMS: To validate the bioelectrical impedance spectroscopy (BIS) model against dual-energy X-ray absorptiometry (DXA), to develop and compare BIS estimates of skeletal muscle mass (SMM) to other prediction equations, and to report BIS reference values of body composition in a population-based sample of 75-year-old Swedes. METHODS: Body composition was measured by BIS in 574 subjects, and by DXA and BIS in a subset of 98 subjects. Data from the latter group was used to develop BIS prediction equations for total body skeletal muscle mass (TBSMM). RESULTS: Average fat free mass (FFM) measured by DXA and BIS was comparable. FFM(BIS) for women and men was 40.6kg and 55.8kg, respectively. Average fat free mass index (FFMI) and body fat index (BFI) for women were 15.6 and 11.0. Average FFMI and BFI for men were 18.3 and 8.6. Existing bioelectrical impedance analysis equations to predict SMM were not valid in this cohort. A TBSMM prediction equation developed from this sample had an R(pred)(2) of 0.91, indicating that the equation would explain 91% of the variability in future observations. CONCLUSIONS: BIS correctly estimated average FFM in healthy elderly Swedes. For prediction of TBSMM, a population specific equation was required

Bioelectrical impedance spectroscopy in growth hormone-deficient adults.

This study evaluated water compartment assessment by bioelectrical impedance spectroscopy (BIS) by Xitron 4000B in 164 growth hormone-deficient adults on growth hormone replacement therapy, examined the assumed constant body density and gender-specific resistivities in BIS methodology and evaluated a published BMI-adjusted BIS equation. Body composition was measured by BIS, total body potassium (TBK), tritium dilution and dual-energy x-ray absorptiometry (DXA). Tritium dilution and TBK were combined to a reference method for water compartments. Average difference for total body water (TBW) by tritium dilution and by BIS was 0.6 l in women (p > 0.05) and -0.2 l in men (p > 0.05). Average extracellular water (ECW) by the reference method and by BIS differed 1.5 l in women (

Body fat mass and the proportion of very large adipocytes in pregnant women are associated with gestational insulin resistance.

Pregnancy is accompanied by fat gain and insulin resistance. Changes in adipose tissue morphology and function during pregnancy and factors contributing to gestational insulin resistance are incompletely known. We sought to characterize adipose tissue in trimesters 1 and 3 (T1/T3) in normal weight (NW) and obese pregnant women, and identify adipose tissue-related factors associated with gestational insulin resistance

A randomized longitudinal dietary intervention study during pregnancy: effects on fish intake, phospholipids, and body composition

BackgroundFish and meat intake may affect gestational weight gain, body composition and serum fatty acids. We aimed to determine whether a longitudinal dietary intervention during pregnancy could increase fish intake, affect serum phospholipid fatty acids, gestational weight gain and body composition changes during pregnancy in women of normal weight participating in the Pregnancy Obesity Nutrition and Child Health study. A second aim was to study possible effects in early pregnancy of fish intake and meat intake, respectively, on serum phospholipid fatty acids, gestational weight gain, and body composition changes during pregnancy.MethodsIn this prospective, randomized controlled study, women were allocated to a control group or to a dietary counseling group that focused on increasing fish intake. Fat mass and fat-free mass were measured by air-displacement plethysmography. Reported intake of fish and meat was collected from a baseline population and from a subgroup of women who participated in each trimester of their pregnancies. Serum levels of phospholipid arachidonic acid (s-ARA), eicosapentaenoic acid (s-EPA), and docosahexaenoic acid (s-DHA) were measured during each trimester.ResultsWeekly fish intake increased only in the intervention group (n = 18) from the first to the second trimester (median difference 113 g, p = 0.03) and from the first to the third trimester (median difference 75 g, p = 0.01). In the first trimester, fish intake correlated with s-EPA (r = 0.36, p = 0.002, n = 69) and s-DHA (r = 0.34, p = 0.005, n = 69), and meat intake correlated with s-ARA (r = 0.28, p = 0.02, n = 69). Fat-free mass gain correlated with reported meat intake in the first trimester (r = 0.39, p = 0.01, n = 45).ConclusionsDietary counseling throughout pregnancy could help women increase their fish intake. Intake of meat in early pregnancy may increase the gain in fat-free mass during pregnancy

A randomized longitudinal dietary intervention study during pregnancy: effects on fish intake, phospholipids, and body composition

BackgroundFish and meat intake may affect gestational weight gain, body composition and serum fatty acids. We aimed to determine whether a longitudinal dietary intervention during pregnancy could increase fish intake, affect serum phospholipid fatty acids, gestational weight gain and body composition changes during pregnancy in women of normal weight participating in the Pregnancy Obesity Nutrition and Child Health study. A second aim was to study possible effects in early pregnancy of fish intake and meat intake, respectively, on serum phospholipid fatty acids, gestational weight gain, and body composition changes during pregnancy.MethodsIn this prospective, randomized controlled study, women were allocated to a control group or to a dietary counseling group that focused on increasing fish intake. Fat mass and fat-free mass were measured by air-displacement plethysmography. Reported intake of fish and meat was collected from a baseline population and from a subgroup of women who participated in each trimester of their pregnancies. Serum levels of phospholipid arachidonic acid (s-ARA), eicosapentaenoic acid (s-EPA), and docosahexaenoic acid (s-DHA) were measured during each trimester.ResultsWeekly fish intake increased only in the intervention group (n = 18) from the first to the second trimester (median difference 113 g, p = 0.03) and from the first to the third trimester (median difference 75 g, p = 0.01). In the first trimester, fish intake correlated with s-EPA (r = 0.36, p = 0.002, n = 69) and s-DHA (r = 0.34, p = 0.005, n = 69), and meat intake correlated with s-ARA (r = 0.28, p = 0.02, n = 69). Fat-free mass gain correlated with reported meat intake in the first trimester (r = 0.39, p = 0.01, n = 45).ConclusionsDietary counseling throughout pregnancy could help women increase their fish intake. Intake of meat in early pregnancy may increase the gain in fat-free mass during pregnancy