Research Article: High-molecular-weight adiponectin levels in healthy, community-dwelling, elderly Japanese volunteers: a 5-year prospective observational study

Date Published: October 19, 2017

Publisher: Springer International Publishing

Author(s): Hiromasa Otsuka, Mitsuru Yanai, Hiroki Kobayashi, Akira Haketa, Motohiko Hara, Kaoru Sugama, Kimitoshi Kato, Masayoshi Soma.

http://doi.org/10.1007/s40520-017-0840-6

Abstract

Serum adiponectin levels are associated with frailty and cardiovascular diseases. Longitudinal changes in adiponectin levels might enhance our understanding of age-related conditions and diseases.

This prospective observational study aimed to: (1) elucidate age-related changes in high-molecular-weight (HMW) adiponectin levels; and (2) identify variables predictive of elevated HMW adiponectin levels and the association with well-known adiponectin single-nucleotide polymorphisms (SNPs) in healthy, elderly Japanese participants.

Healthy elderly volunteers (n = 196; 55 men and 141 women; median age 72.0 years; range 69.0–75.0 years) underwent anthropometric and physical function measurements, as well as laboratory tests at baseline and the 5-year follow-up.

HMW adiponectin levels were significantly higher in women than in men (8.4, 5.3–11.9 vs. 5.7, 3.1–9.0 μg/mL; p < 0.001) at baseline and decreased significantly at follow-up in women (7.7, 4.8–11.2 μg/mL; p < 0.001), but not in men. In the multiple regression analysis, high-density lipoprotein cholesterol levels and body weight were independent predictors of HMW adiponectin levels. The rate of change in HMW adiponectin levels was inversely correlated with the rates of change in body weight, body mass index, and knee leg extension strengths, and positively correlated with rates of change in high-density lipoprotein cholesterol and one-leg standing time. There were no significant differences in HMW adiponectin levels among SNPs. Decreasing HMW adiponectin levels might lead to an increased risk of cardiovascular diseases in elderly women. HMW adiponectin levels significantly decreased over a 5-year period in community-dwelling elderly Japanese women.

Partial Text

Adiponectin is an adipose tissue-derived specific protein encoded by the adiponectin gene (ADIPOQ) located on chromosome 3q27 in a region identified as a susceptibility locus for metabolic syndrome [1]. Serum levels of adiponectin have been associated with glucose intolerance, diabetes mellitus, and cardiovascular diseases (CVD) [2, 3]. Common single-nucleotide polymorphisms (SNPs) at the ADIPOQ locus (SNP + 45T/G and SNP + 276G/T) have also been associated with low adiponectin levels, insulin resistance, and diabetes mellitus in a Japanese population [4].

Table 1 presents the baseline and follow-up characteristics of all participants, as well as those for men and women separately. The proportion of current smokers and regular exerciser comprised 10 and 15.9% of the participants, respectively. Among all participants, the median HMW adiponectin and bone mineral density values, as well as all measured physical functions were significantly decreased at the 5-year follow-up. Height, body weight, and BMI were also significantly decreased for all participants. In contrast, there was no significant change in the mean waist circumference and non-HDL cholesterol levels. HMW adiponectin levels at baseline were inversely correlated with height (rs = − 0.291; p < 0.001), body weight (rs = − 0.338; p < 0.001), BMI (rs = − 0.190; p = 0.008), hand grip strength (rs = − 0.234; p = 0.001), and knee extension strength (rs = − 0.177; p = 0.014). Conversely, HDL cholesterol levels were positively correlated with baseline HMW adiponectin levels (rs = 0.400; p < 0.001). In this study, we determined that the HMW adiponectin levels were significantly decreased in women but not men during the 5-year follow-up period, and body weight and HDL cholesterol as predictors of HMW adiponectin levels. Previous studies have also reported that body weight and HDL cholesterol were correlated with adiponectin levels, consistent with our results [5, 16]. However, longitudinal HMW adiponectin levels were significantly lower, despite the decreased body weight and inverse correlation between body weight and change in HMW adiponectin levels. The proportion of body weight reduction observed in this study was low compared to that observed in other studies. Therefore, a reduction in body weight might have had a weak effect of the HMW adiponectin levels in the current study. Since body weight reduction in healthy elderly individuals is low, it might be unrelated to longitudinal changes in adiponectin levels. Therefore, the plasma HMW adiponectin levels were longitudinally and significantly decreased in elderly Japanese women. These findings may indicate an increased risk of CVD in elderly women. Further studies are necessary to determine the underlying mechanisms of age- and sex-related changes in adiponectin levels and their association with CVD and frailty in elderly populations.   Source: http://doi.org/10.1007/s40520-017-0840-6

 

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