Results from a recent study of patients with type 2 diabetes showed that higher waist-to-calf ratios increased the risk for nonalcoholic fatty liver disease, fibrosis and sarcopenia, independent of insulin resistance.
“Loss of skeletal muscle mass, reduced strength and increasing fat mass often associated with aging can induce insulin resistance and increase risk of developing obesity-related comorbidities such as NAFLD and diabetes,” the researchers wrote. “As sarcopenic obesity is strongly related to cardiometabolic disease, estimation of abdominal fat and leg mass by measuring waist-to-calf circumference ratio may be a useful index that simply indicates sarcopenic obesity.”
To assess the use of waist-to-calf ratio as a predictor of NAFLD and fibrosis, the researchers enrolled 5,507 patients with type 2 diabetes. The researchers measured steatosis with abdominal ultrasound and calculated fibrosis with noninvasive serum biomarker-based models.
Mean patient age was 56.8 years, 51% were men, average duration of diabetes was 8.1 years and 2,555 had NAFLD. Those with NAFLD had greater waist circumference (87.1 vs. 80.1 cm; P < .001), calf circumference (35.4 vs. 33.8; P < .001) and waist-to-calf ratio measurements (2.46 vs. 2.37; P < .001) compared with those without NAFLD.
Regardless of sex, the prevalence of NAFLD increased with higher waist-to-calf ratio tertiles: 54% of men and 58% of women in the highest tertile compared with 36% of men and 28% of women in the lowest tertile. Similarly, alanine aminotransferase and aspartate aminotransferase levels, c-reactive protein and white blood cell count were increased in the highest waist-to-calf tertiles compared with the lowest tertile, regardless of sex (P < .001). Those in the highest tertile were also more likely to have fibrosis (P < .001).
After multivariate adjustment, the prevalence of NAFLD (OR = 1.43; 95% CI, 1.22-1.68) and the risk for significant fibrosis (OR = 1.56; 95% CI, 1.31-1.86) according to FIB-4 were significantly increased in the highest waist-to-calf ratio tertile.
Skeletal muscle mass index was significantly decreased among those with NAFLD (39.2 vs. 40.9; P < .001) and the prevalence of sarcopenia was higher (26.4% vs. 14.2%; P < .001) compared with those without NAFLD. After multivariate analysis, researchers observed that the middle (OR = 1.73; 95% CI, 1.36-2.21) and the highest waist-to-calf ratio tertiles (OR = 3.18; 95% CI, 2.5-4.05) were correlated with an increased risk for sarcopenia.
According to the researchers, experiments have shown that obesity induced by western diet leads to sarcopenia, NAFLD and hepatic necroinflammation compared with control diets. “Consequently, those factors of [type 2 diabetes], abdominal obesity and reduced lean body mass all combine to increase the risk of fatty liver development,” they wrote.
“The simple, noninvasive method of measuring waist circumference is easily applied in the outpatient clinic, and previous studies proved the efficacy of waist circumference to predict cardiovascular risk and related mortality,” the researchers concluded. “It could be used clinically as a simple marker to inform treatment decisions.” – by Talitha Bennett
Disclosure: The authors report no relevant financial disclosures.