Sarcopenia is associated with albuminuria independently of hypertension and diabetes: KNHANES 2008-2011.

INTRODUCTION: Although sarcopenia is associated with metabolic disorders, its influence on albuminuria has not been determined. The aim of this study was to identify the relationship between sarcopenia and albuminuria in the general population.

METHODS: This was a population-based, cross-sectional study using a nationally representative sample of 2326 subjects aged ≥20years from the Korea National Health and Nutrition Examination Surveys of 2008-2011. Appendicular skeletal muscle (ASM) measured by dual-energy X-ray absorptiometry was used to assess sarcopenia, which was defined as ASM divided by body mass index, as recommended by the international consensus meeting of the National Institutes of Health. Albuminuria was defined as an albumin-to-creatinine ratio of ≥30mg/g using random spot urine samples.

RESULTS: A total of 385 (16.5%) subjects were classified as having albuminuria. Sarcopenic subjects showed a higher proportion of albuminuria than subjects without sarcopenia (odds ratios [ORs]=2.17-3.26, all P<0.05) after stratification based on the presence of hypertension, diabetes, or metabolic syndrome and a higher homeostasis model assessment of insulin resistance (all P<0.001). The albuminuria risk was comparable between insulin-sensitive subjects with sarcopenia and insulin-resistant subjects with preserved muscle mass. A multiple logistic regression analysis also demonstrated that sarcopenia was independently associated with albuminuria (OR=1.61, 95% confidence interval [CI]=1.04-2.48, P<0.05). The association between sarcopenia and albuminuria remained strong in the elderly population (ORs=1.80-2.68, P<0.05), whereas it lost its significance in the younger age group. Furthermore, the risk of albuminuria was much higher in sarcopenic obese subjects than in other groups (OR=4.90, 95% CI=3.23-7.43, P<0.001).

CONCLUSIONS: Sarcopenia was associated with an increased risk of albuminuria independent of hypertension, diabetes, and metabolic syndrome. Sarcopenia and obesity had a synergistic impact on the increased risk of albuminuria. This suggests that sarcopenic obesity as well as sarcopenia alone may be considered as novel risk factors for albuminuria.