Handgrip Strength and Factors Associated in Poor Elderly Assisted at a Primary Care Unit in Rio de Janeiro, Brazil.

INTRODUCTION: Sarcopenia is a condition diagnosed when the patient presents low muscle mass, plus low muscle strength or low physical performance. Muscle weakness in the oldest (dynapenia) is a major public health concern because it predicts future all-cause mortality and is associated with falls, disability, cardiovascular mortality and morbidity. Grip strength is a simple method for assessment of muscle function in clinical practice.

OBJECTIVE: To estimate the grip strength and identify factors associated with handgrip strength variation in elderly people with low socioeconomic status.

METHODS: Cross-sectional study based on a multidimensional assessment of primary care users that were 60 years or older. The sample size was calculated using an estimated prevalence of depression in older adults of 20%. A kappa coefficient of 0.6 with a 95% confidence interval was used to generate a conservative sample size of 180 individuals. Procedures: tests and scales to assess humor, cognition (MMSE), basic (ADL) and instrumental activities (IADL) of daily living, mobility (Timed Up and Go), strength, height, Body Mass Index (BMI) and social support were applied. Questions about falls, chronic diseases and self-rated health (SRH) were also included. Statistical Analysis: Mean, standard deviation and statistical tests were used to compare grip strength means by demographic and health factors. A multivariate linear model was used to explain the relationship of the predictors with grip strength.

RESULTS: The group was composed predominantly by women (73%) with a very low level of education (mean 3 years of schooling), mean age of 73.09 (± 7.05) years old, good mobility and without IADL impairment. Mean grip strength of male and female were 31.86Kg (SD 5.55) and 21.69Kg (SD 4.48) [p- 0.0001], respectively. Low grip strength was present in 27.7% of women and 39.6% of men. As expected, men and younger participants had higher grip strength than women and older individuals. In the adjusted model, age (p- 0.03), female sex (p- 0.0001), mobility (p- 0.05), height (p- 0.03) and depression (p- 0.03) were independently associated with low grip strength. For every second more in the mobility test, there was a mean decrease of 0.08 Kg in the grip strength. Elders with depression had a mean reduction of 1.74Kg in the grip strength in relation to those in the comparison groups. There was an average reduction of 8.36Kg in the grip strength of elderly females relative to males. For each year of age after 60 years, it was expected an average reduction of 0.11 Kg in the grip strength.

CONCLUSION: our results suggest that low grip strength is associated with age, female sex, height, depression and mobility problems in poor elderly. Grip strength can be a simple, quick and inexpensive means of stratifying elders' risk of sarcopenia in the primary care setting. Efforts should be made to recognize weaker persons and the conditions associated to low grip strength in order to target early interventions to prevent frailty and disability.