Muscle weakness is a good predictor of disability in the older population. A study investigates recently proposed cut-points for muscle weakness as predictors of future disability.
A strong determinant of age-related decreased function is muscle weakness. It is linked to mobility disability, cardiovascular disease, and premature mortality. A reliable and cost-effective method to assess overall muscle strength is hand grip strength, which can also be used as a prognostic measure of future functional limitations.
Recent studies have established cut-points for clinical muscle weakness that are nationally representative of all genders and races found in Americans older than 65 years. These cut-points have not yet been tested to determine if they can accurately predict future disability. A recent study carried out in the U.S and published in The Journal of Nutrition, Health & Aging has aimed to do just that. Researchers examined whether grip strength can predict physical disability in a sample of Americans aged 65 years and over. The main outcome of interest was disability dynamics, which was characterized by changes in activities of daily living (ADL) across a two-year period.
This study consisted of approximately 8,725, of which 44% of participants were classed as weak at the beginning of the study. During the follow-up, 55% maintained their independence as no change in their ADL status was observed, 11% had developed a new disability and 4% experienced an increase in their disability status. The risk of developing ADL disability was 54% higher within individuals who were weak compared with those who were not weak at the beginning of the study.
The results of this study support past studies, which found that older individuals with muscle weakness, as identified by race/sex-specific population-derived cut-points, have a higher risk of experiencing a decline in their ability to carry out basic self-care activities of daily living over a two year period. The authors found that there is a strong link between muscle weakness and the onset, progression, and persistence of physical disability, which emphasizes the need for effective screening that can identify those at increased risk from clinical muscle weakness as they get older.
The authors state that to the best of their knowledge, this is the first study of its kind examining the rate of onset of disability, progression, and continuation in association with muscle weakness in a nationally representative sample of older Americans.
This is the first study conducted using muscle weakness cut-points in a nationally- representative population of older Americans. It establishes that clinical muscle weakness is strongly associated with future disability status, and is thus able to identify which individuals are at an increased risk of developing and experiencing persistence in their disability status later in life. The results of this study highlight the need to use population-specific cut-points to determine those individuals at increased risk of disability.
Written by Jade Marie Evans, MPharm, Medical Writer
Duchowny K.A et al . (2017). Muscle weakness and physical disability in older Americans: Longitudinal findings from the U.S. Health and retirement study. Available: https://link.springer.com/article/10.1007/s12603-017-0951-y. Last accessed 30th Aug 2017.