Associations of birth weight with dual-energy x-ray absorptiometry-determined body composition, bone densitometry and cardiometabolic risk profile in young women from the Nutritionists' Health Study

ABSTRACT

Background: Visceral adiposity is a risk factor for cardiometabolic diseases and dual-energy x-ray absorptiometry (DXA) represents precise method for measuring visceral adipose tissue (VAT), muscle and bone compartments. The musculoskeletal system deteriorates with aging and may result in osteosarcopenia. Since known risk factors do not fully explain the occurrence of osteosarcopenia, the search for new causal factors, as birth weight (BW) is promising. Objectives: To evaluate whether BW was associated with DXA-determined body composition, bone densitometry and cardiometabolic risk markers in young women from the NutriHS. Paper 1 objective: to propose reference values for DXA-determined VAT, and to test their ability to identify the cardiometabolic risk profile. Paper 2 to examine whether BW was associated with muscle and bone DXA-determined parameters. Paper 3 to investigate whether parameters of muscle and bone compartments were associated and possible predictive factors of these compartments throughout life. Methods: NutriHS is a cohort study conducted in undergraduates and Nutrition graduates and here cross-sectional analyses were performed in 201 healthy women (20-45 years). They answered questionnaires and had anthropometry, muscle strength and performance, DXA-determined body composition and bone densitometry obtained. A random sample of 148 participants had also laboratory tests collected. Multiple regression models, using the directed acyclic graphs-recommended adjustments, were employed. Results: Median age was 23 years and mean BMI was 22.9±2.9 kg/m2. Paper 1 Mean VAT mass and volume were 221.0±306.1 g and 231.8±323.8 cm3, respectively. The third tertiles of VAT were significantly associated with increased frequencies of abnormal anthropometry, HOMA-IR and TyG indexes. Paper 2 Mean BW was 3,199±424 g; BW in quartiles was significantly associated with several muscle and bone parameters. Paper 3 Direct, strong and independent associations between bone and muscle variables were detected. Discussion: Cutoffs for DXA-derived VAT mass (221.0 g) and volume (231.8 cm3) are being suggested for Brazilian young women; these seem able to disclose a mild visceral fat accumulation, prior the deterioration of glucose and lipid metabolism. The role of BW as an early marker for muscle and bone states in young adulthood was shown. In addition, a musculoskeletal profile for a healthy stratus of the Brazilian women was firstly described. Our findings indicated a muscle-bone crosstalk even in young adults and suggested predictive factors (such as BW, physical activity, smoking) of muscle and bone compartments