Handgrip strength reference values and determinants of muscle weakness in French adults: results from the NutriNet-Santé study.

Abstract

Background: The aim of this study was to determine sex- and age-specific handgrip strength percentiles in French adults and investigate sociodemographic and anthropometric variables associated with lower upper arm strength.

Methods: A sample of 18,532 French adults (5262 men, 13,090 women), aged 18-91, from the NutriNet-Santé cohort (2011-2014) was assessed for handgrip strength. For each hand, the maximum grip strength in kilograms was recorded. Grip strength was analyzed in absolute terms and relative units (relative to body weight and BMI). Percentiles (5^th to 95^th) were established by age and sex. Sociodemographic, lifestyle, and anthropometric factors associated with low handgrip strength (<20^th percentile) were evaluated using logistic regression, considering age, education, income, smoking status, BMI, physical activity, and sitting time.

Results: Low BMI was linked to low handgrip strength in both sexes, whereas overweight was protective in men (OR 0.77). In women, lower education correlated with higher odds of low strength (OR 0.78-0.84). Male former or current smokers had higher odds of low grip strength (OR 1.20-1.35), while women showed an inverse association (OR 0.86). Physical activity reduced risk in both sexes, particularly at high activity levels (men OR 0.74; women OR 0.73). Age was a key factor in women, with increased odds in the 45-49 and 55-59 age groups (OR 1.27 and 1.32).

Conclusions: The reference values provide reference data for French adults, and these data should be useful in identifying populations at risk of low muscle strength and sarcopenia.