Association between Physical Activity and Health Outcomes (High Body Fatness, High Blood Pressure) in Namibian Adolescents and Adult women

Regular physical activity (PA) is known to promote the physical and mental health of children and adolescents and further prevent the development of health problems in adulthood. Information on body composition and PA is crucial for health promotion strategies and for epidemiological studies informing policies. However, there is limited data on the association between body composition and PA in Namibia. This dearth of published data is a significant shortcoming in the development of strategies and policies to promote PA in Namibia. Therefore, this cross-sectional study was conducted to determine the association between PA as a dependent variable and independent variables such as high blood pressure and body fatness as measured by different methods (gold standard deuterium dilution, body mass index, mid upper arm circumference, and waist circumference). The study included 206 healthy adolescent girls aged 13-19 years and 207 young adult females aged 20-40 years from Windhoek, Namibia. PA was measured using the PACE+ questionnaire in adolescents, and the GPAQ questionnaire was used for adults. In adolescents, only 33% of the participants met the recommended guidelines for PA, compared to only 2% for adults. Nevertheless, the study found no statistically significant association between PA and blood pressure indices (p-value < 0.05) among adolescents and adults. However, there was a significant association between PA and high body fatness (p-value < 0.001) and waist circumference (p-value = 0.014) in adolescents. Among adults, PA was significantly related to waist circumference only. In conclusion, failure to meet recommended PA guidelines is strongly associated with abdominal obesity and high body fatness. The knowledge gained from this study may be used by policymakers in the development of strategic policies and interventions aimed at promoting PA as a public priority and improving health outcomes.

Role of adiponectin gene variants, adipokines and hydrometry-based percent body fat in metabolically healthy and abnormal obesity

OBJECTIVE

Metabolically healthy obesity (MHO) subjects have better metabolic parameters than metabolically abnormal obesity (MAO) subjects, but the possible mechanisms underlying this remain unknown. Our study was designed to investigate the interrelationships among genes, adipokines, body fat and its distribution in MHO and MAO.

METHODS

From 2007 to 2009, 103 males and 131 females aged 18-50 years were enrolled by an intention-to-treat design in a weight management clinic. Participants were divided into MHO and MAO groups. Percent body fat (PBF) was measured by a deuterium oxide dilution method. Four polymorphic variants, including PPARγ2 (Pro12Ala and C1431T) and adiponectin (T45G and G276T) genes, and three adipokines (adiponectin, leptin and resistin) were obtained.

RESULTS

Of the 234 obese subjects, 130 (55.6%) were MHO. In the univariate analysis, the MAO group has significantly higher anthropometric, metabolic indices and leptin levels than the MHO group. Logistic regression analysis revealed that age, male gender, the T allele of adiponectin T45G polymorphism, leptin and PBF were positively associated with MAO. ANCOVA analysis revealed that the T allele of adiponectin T45G polymorphism was associated with higher fasting and postprandial glucose levels. We further found that TT genotype has a lower high molecular weight (HMW)/low molecular weight (LMW) adiponectin ratio than GG genotype.

CONCLUSIONS

The factors associated with MAO are age, male gender, the T allele of adiponectin T45G polymorphism, leptin, and PBF. The net effects of T45G polymorphism on the MAO phenotype may be achieved by changes in the adiponectin oligomer ratio and glucose levels.

Assessment of body composition in Indian adults: comparison between dual-energy X-ray absorptiometry and isotope dilution technique

Dual-energy X-ray absorptiometry (DXA) and isotope dilution technique have been used as reference methods to validate the estimates of body composition by simple field techniques; however, very few studies have compared these two methods. We compared the estimates of body composition by DXA and isotope dilution (¹⁸O) technique in apparently healthy Indian men and women (aged 19–70 years, n 152, 48 % men) with a wide range of BMI (14–40 kg/m²). Isotopic enrichment was assessed by isotope ratio mass spectroscopy. The agreement between the estimates of body composition measured by the two techniques was assessed by the Bland–Altman method. The mean age and BMI were 37 (sd 15) years and 23·3 (sd 5·1) kg/m², respectively, for men and 37 (sd 14) years and 24·1 (sd 5·8) kg/m², respectively, for women. The estimates of fat-free mass were higher by about 7 (95 % CI 6, 9) %, those of fat mass were lower by about 21 (95 % CI − 18, − 23) %, and those of body fat percentage (BF%) were lower by about 7·4 (95 % CI − 8·2, − 6·6) % as obtained by DXA compared with the isotope dilution technique. The Bland–Altman analysis showed wide limits of agreement that indicated poor agreement between the methods. The bias in the estimates of BF% was higher at the lower values of BF%. Thus, the two commonly used reference methods showed substantial differences in the estimates of body composition with wide limits of agreement. As the estimates of body composition are method-dependent, the two methods cannot be used interchangeably.