Glucose Levels as a Mediator of the Detrimental Effect of Abdominal Obesity on Relative Handgrip Strength in Older Adults

Abstract

Excess central adiposity accelerates the decline of muscle strength in older people. Additionally, hyperglycemia, independent of associated comorbidities, is related to the loss of muscle mass and strength, and contributes to functional impairment in older adults. We studied the mediation effect of glucose levels, in the relationship between abdominal obesity and relative handgrip strength (HGS). A total of 1571 participants (60.0% women, mean age 69.1 ± 7.0 years) from 86 municipalities were selected following a multistage area probability sampling design. Measurements included demographic and anthropometric/adiposity markers (weight, height, body mass index, and waist circumference). HGS was measured using a digital dynamometer for three sets and the mean value was recorded. The values were normalized to body weight (relative HGS). Fasting glucose was analyzed by enzymatic colorimetric methods. Mediation analyses were performed to identify associations between the independent variable (abdominal obesity) and outcomes (relative HGS), as well as to determine whether fasting glucose levels mediated the relationship between excess adiposity and relative HGS. A total of 1239 (78.8%) had abdominal obesity. Abdominal obesity had a negative effect on fasting glucose (β = 9.04, 95%CI = 5.87 to 12.21); while fasting glucose to relative HGS was inversely related (β = −0.003, 95%CI = −0.005 to −0.001), p < 0.001. The direct effect of abdominal obesity on relative HGS was statistically significant (β = −0.069, 95%CI = −0.082 to −0.057), p < 0.001. Lastly, fasting glucose levels mediates the detrimental effect of abdominal obesity on relative HGS (indirect effect β = −0.002, 95%CI = −0.004 to −0.001), p < 0.001. Our results suggest that the glucose level could worsen the association between abdominal obesity status and lower HGS. Thus, it is plausible to consider fasting glucose levels when assessing older adults with excess adiposity and/or suspected loss of muscle mass.

Obesity, Even in the Metabolically Healthy, Increases the Risk of Poor Physical Performance: A Cross-Sectional Study of Older People in a Chinese Community

“…32 Other studies have also shown a negative correlation between excess abdominal adiposity, higher levels of glucose and triglycerides, and grip strength. 25,33 Furthermore, our study found that abdominal obesity explained (35.4%) changes in relative grip strength more than the other four metabolic components. In addition, our research result was consistent with other studies 31,34 showing that the MetS-relative grip strength association was mainly mediated by abdominal obesity.…”

“…This result supports previous evidence in the elderly that has shown the negative effect of obesity on grip strength. 15 , 25 Some biological pathways (eg, inflammation, sex-specific hormones, anabolic resistance, and muscle denervation) likely contribute to obesity-induced muscle weakness. 26 , 27 Moreover, the identification of genetic variants for body fat metabolism may also provide an understanding of the development of physical limitations.…”

Association between relative handgrip strength and abdominal obesity, type-2 diabetes and hypertension in a Mexican population

“…Similarly, it has been reported that the direct effect of AO on R HGS was statistically significant. In addition, this study suggests that high glucose levels could worsen the association between AO status and lower HGS (31).…”

“…A recent study identifies a strong relationship between R HGS and the prevalence of MetS in adults, regardless of sex (36). On the other hand, in older adults, fasting glucose is inversely related to R HGS (31). Also, subjects with higher R HGS had a lower risk of HT, T2D and dyslipidemia than those with lower HGS (11).…”

Association between Adjusted Handgrip Strength and Metabolic Syndrome in Arab Men

“…Moreover, hyperglycemia and excess central adiposity are two independent factors that accelerate the decline in muscle mass and strength. Data showed that abdominal obesity was inversely associated with fasting glucose, and fasting glucose was inversely associated with HGS; thus, the fasting glucose level mediates the relationship between abdominal obesity and HGS [37]. Thus, causality between HGS and cardiometabolic markers, as well as their interaction with body composition, requires further prospective studies.…”