Age-related anthropometric remodelling resulting in increased and redistributed adiposity is associated with increases in the prevalence of cardiovascular risk factors in Chinese subjects

Changes in adiposity in an older Chinese population in rapid economic transition

OBJECTIVE

To examine the changes in body mass index (BMI) and waist circumference (WC) in Guangzhou, South China, which is probably experiencing the most rapid economic transition in history.

METHODS

In this study, 17,786 Chinese aged 50+ years were recruited from 2003 to 2008 and followed up until 2012. BMI and WC were measured at two time points.

RESULTS

During the mean follow-up of 3.6 years (median = 3, interquartile = 1), age-adjusted mean BMI increased only slightly. By contrast, mean WC increased sharply by 0.94 cm (95% confidence interval 0.93-0.94) annually in men and 1.29 cm (1.28-1.29) annually in women. In 77% of women and 69% of men, WC increased, and among them, the mean annual increase was 2.01 cm and 1.70 cm, respectively. Among healthy, never-smoking participants, the incidence of central obesity was 29.0% (36.4% in women and 14.2% in men). The incidence of general obesity was 1.9% and was similarly low in both men and women (2.1% vs. 1.8%). Conversely, 20.3% of individuals with general obesity became nonobese, and 12.8% of individuals with central obesity returned to normal.

CONCLUSIONS

Central obesity has risen sharply in this cohort. Such increases may have been greatly underestimated previously and should form the basis of an even stronger warning for regions undergoing economic transitions in China and elsewhere.

Interleukin-6 receptor gene polymorphism modulates interleukin-6 levels and the metabolic syndrome: GBCS-CVD

Interleukin-6 (IL-6) is a key pleiotropic cytokine that modulates the inflammatory response. Single-nucleotide polymorphisms (SNPs) within associated genes may contribute to the metabolic syndrome (MES). We examined the role of the IL-6 (rs1524107-C/T) and IL-6 receptor (IL-6R, rs8192284-A/C, Asp358Ala) SNPs in modulating IL-6 levels and the syndrome. A total of 1,979 older Chinese subjects aged 50-92 years from Guangzhou Biobank Cohort Study (GBCS) were recruited. SNPs were detected using Taqman SNP genotyping kits. IL-6 was measured using enzyme-linked immunosorbent assay. The genotype frequencies were 4.9, 33.9, and 61.3% for the IL-6 CC, CT, and TT, and 12.0, 44.9, and 43.1% for the IL-6R CC, AC, and AA, respectively. Both SNPs were in Hardy-Weinberg equilibrium. The IL-6 SNP was not associated with IL-6 levels or the MES, but was dose-dependently associated with fibrinogen levels, P = 0.049. IL-6 levels significantly decreased with increasing proportions of the IL-6R A-allele 9.8 ± 4.9, 9.3 ± 4.8, and 8.4 ± 4.3, respectively, P = 0.001. Conversely, the A-allele was associated with elevated triglyceride, P = 0.009, C-reactive protein, P = 0.047, and potentially with fasting glucose levels, P = 0.077. There was an increasing prevalence of the MES in those carrying the IL-6R CC, AC, and AA genotypes at 18.1, 21.5, 25.2%, respectively, P = 0.010. The SNP was a significant independent predictor of the MES after adjusting for general obesity, age, gender and lifestyle, and socioeconomic parameters, P = 0.023. These data, which are in accord with studies from white populations suggest the IL-6R SNP may play a role in the pathogenesis of the MES possibly through modulating IL-6 levels.

Lifestyle factors associated with age-related differences in body composition: the Florey Adelaide Male Aging Study

BACKGROUND

Age-related change in body composition is associated with adverse health outcomes, including functional decline, disability, morbidity, and early mortality. Prevention of age-related changes requires a greater understanding of the associations among age, lifestyle factors, and body composition.

OBJECTIVE

We aimed to comprehensively determine lifestyle factors associated with age-related differences in body composition assessed by using dual-energy X-ray absorptiometry.

DESIGN

We analyzed baseline (cross-sectional) data collected from 2002 to 2005 for approximately 1200 men in the Florey Adelaide Male Aging Study, a regionally representative cohort of Australian men aged 35-81 y.

RESULTS

Mean values for whole-body lean mass (LM) and areal bone mineral density (aBMD) decreased, whereas mean values for abdominal fat mass (FM) and whole-body and abdominal percentage FM (%FM) increased with age. No significant age-related differences were found for whole-body FM. Multiple adjusted odds of being in the highest tertiles for whole-body and abdominal %FM decreased for smokers (63-71%) but increased with age group and for lowest energy (43-50%), carbohydrate (92-107%), and fiber (107%) intake tertiles. Multiple adjusted odds of being in the highest aBMD tertile decreased for lowest body mass (92%) and carbohydrate intake (63%) tertiles and for men aged > or = 75 y (78%) but increased for Australian birth (58%) and for participation in vigorous physical activities (82%).

CONCLUSIONS

Age-related differences in body composition indicate that whole-body FM remains stable but increases viscerally and that whole-body %FM is confounded by LM, whereas aBMD decreases with age. Age-related differences in %FM and aBMD are associated with demographic and lifestyle factors.

Implications of increased weight and waist circumference on vascular risk in an older Chinese population: the Guangzhou Biobank Cohort Study

BACKGROUND

The relationships between weight and waist on vascular risk are well described, but the long-term impact of these parameters is less clearly defined, particularly in Chinese populations.

METHODS

Ten thousand four hundred and ten older subjects (50-85 years) were recruited and blood pressure, anthropometric, and fasting vascular risk factors measured. Socioeconomic and demographic data, including self-reported weight and waist gain since 18 years. The association of weight and waist gain with these vascular risk factors was analysed.

RESULTS

Weight, and particularly waist gain were associated with a more adverse vascular risk factor profile, with the most adverse profile associated with gains in both weight and waist. Anthropometric gains were associated with increased risk even in non-obese subjects (p<0.05). Even after adjustment for a range of demographic and socioeconomic factors, waist gain was associated with additional risk of having the metabolic syndrome and its components and self-reported vascular disease in those centrally obese subjects (p<0.05 for all).

CONCLUSION

Increased weight and waist increased the level of vascular risk factors and self-reported disease in both non-obese and obese subjects. The high prevalence of vascular risk factors in this population forewarns of a major developing health burden in the rapidly modernising 1.2 billion Chinese population.