Relationships between Socioeconomic Status, Handgrip Strength, and Non-Alcoholic Fatty Liver Disease in Middle-Aged Adults

Abstract

Although low socioeconomic status (SES) and decreased muscle strength have been found to be associated with the risk factors of non-alcoholic fatty liver disease (NAFLD), including insulin resistance, obesity, and metabolic syndrome, the associations among SES, muscle strength, and NAFLD are still unclear. We aimed to investigate the combined effect of SES and relative handgrip strength (HGS) on the risk of NAFLD in middle-aged adults. Data from 5272 middle-aged adults who participated in the Korea National Health and Nutrition Examination Surveys (KNHANES) from 2014–2018 were analyzed. NAFLD was defined using the hepatic steatosis index (HSI) > 36 and the comprehensive NAFLD score (CNS) ≥ 40 in the absence of other causes of liver disease. SES was based on a self-reported questionnaire. Overall, individuals with low SES (odds ratio (OR) = 1.703, 95% confidence interval (CI): 1.424–2.037, p < 0.001) or low HGS (OR = 12.161, 95% CI: 9.548–15.488, p < 0.001) had a significantly higher risk of NAFLD. The joint association analysis showed that a low SES combined with a low HGS (OR = 2.479, 95% CI: 1.351–4.549, p = 0.003) further significantly increased the risk of NAFLD when adjusted for all the covariates, compared with individuals with a high SES and a high HGS (OR = 1). The current findings suggest that both low SES and low HGS were independently and synergistically associated with an increased risk of NAFLD in middle-aged Korean adults.

Association between Non-Alcoholic Fatty Liver Disease and Mediterranean Lifestyle: A Systematic Review

“…Nine studies analyzed the association between Mediterranean diet, physical activity, and NAFLD; four of them studied recruited people as a single group [ 22 , 25 , 29 , 30 ], two classified participants into two groups [ 24 , 31 ], two analyzed hand-grip strength [ 32 , 33 ], and one assessed renal outcomes [ 26 ]. Most studies agreed that a Mediterranean diet and physical activity improved all or some of NAFLD risk factors: weight reduction [ 22 , 29 , 30 ], body mass index [ 24 , 29 , 30 ], waist circumference [ 24 , 29 , 30 ], triglyceridemia [ 22 , 29 ], LDL-cholesterol [ 29 , 30 , 31 ], impaired fasting glycemia [ 22 , 29 ], visceral adipose index and fatty liver index [ 29 ], lipid accumulation [ 14 , 29 ], homeostatic model assessment-insulin resistance [ 29 , 30 , 31 ]; increased HDL-cholesterol [ 22 , 29 ]; normalization of alanine aminotransferase [ 22 , 29 , 30 ]; reduction of gamma glutamyl transferase [ 30 ]; and improvement of steatosis [ 24 , 29 , 30 , 31 ].…”

“…High hand-grip strength was associated with a decreased risk of NAFLD [ 33 ]. Moreover, NAFLD indexes, such as a simple NAFLD score, hepatic steatosis index, NAFLD fibrosis score, and fibrosis 4 calculator, decreased linearly when hand-grip strength increased [ 32 ].…”

What Do We Know about Inequalities in NAFLD Distribution and Outcomes? A Scoping Review

“…Overall, NAFLD prevalence seems to be higher among individuals with lower socioeconomic position in Western countries [33,34]. However, data coming from Eastern countries is not so consistent [35,36]. A study conducted in South Korea found that people with a low socioeconomic status have a significantly higher risk of developing NAFLD (OR 1.7) [36].…”

“…However, data coming from Eastern countries is not so consistent [35,36]. A study conducted in South Korea found that people with a low socioeconomic status have a significantly higher risk of developing NAFLD (OR 1.7) [36]. A Chinese study also found that people with a higher median income had a 1.96 higher risk of developing NAFLD than the low-income population [35].…”

“…Advanced liver disease is more prevalent in individuals with lower socioeconomic status [33,36,38]. In geographic regions with an overall lower socioeconomic position, there is higher cirrhosis prevalence [38].…”