Grip strength inversely tied to mortality, other health outcomes
Higher grip strength is strongly associated with lower all-cause mortality and reduced incidence of and mortality from cardiovascular disease (CVD), respiratory disease, chronic obstructive pulmonary disease (COPD), all cancer and subtypes of cancer, including colorectal, lung and breast cancer, according to a study, adding that such associations are moderately stronger in younger individuals.
“Our results show that adding handgrip strength to an existing office-based risk score improves the prediction ability for all-cause mortality and incidence of and mortality from CVD and that muscle weakness (using previously defined grip strength cutoffs) is associated with poorer health outcomes,” researchers said.
Over a mean follow-up of 7.1 years (range, 5.3–9.9 years), 13,322 (2.7 percent) out of 502,293 participants (aged 40–69 years; 54 percent women) died. [BMJ 2018;361:k1651]
Hazard ratios (HRs) per 5-kg lower grip strength were greater (p<0.05 for all) for all-cause mortality (women: HR, 1.20; 95 percent CI, 1.17–1.23; men: HR, 1.16; 1.15–1.17) and cause-specific mortality from CVD (women: HR, 1.19; 1.13–1.25; men: HR, 1.22; 1.18–1.26), all respiratory disease (women: HR, 1.31; 1.22–1.40; men: HR, 1.24; 1.20–1.28), COPD (women: HR, 1.24; 1.05–1.47; men: HR, 1.19; 1.09–1.30), all cancer (women: HR, 1.17; 1.13–1.21; men: HR, 1.10; 1.07–1.13), colorectal cancer (women: HR, 1.17; 1.04–1.32; men: HR, 1.18; 1.09–1.27), lung cancer (women: HR, 1.17; 1.07–1.27; men: HR, 1.08; 1.03–1.13), and breast cancer (HR, 1.24; 1.10–1.39) but not prostate cancer (HR, 1.05; 0.96–1.15).
The younger age group showed higher HRs for several of these associations. This inverse relationship between grip strength and mortality is consistent with the findings of previous studies. [BMJ 2010;341:c4467; Lancet 2015;386:266-273; BMJ 2012;345:e7279; J Gerontol A Biol Sci Med Sci 2006;61:72-77; Eur Heart J 2017;38:116-122; Int J Epidemiol 2007;36:228-235; Eur J Epidemiol 2006;21:113-122; BMJ 2014;348:g2219]
Furthermore, an association was observed between muscle weakness (defined as grip strength <26 kg for men and <16 kg for women) and a higher hazard for all health outcomes, except colon cancer in women and prostate cancer and lung cancer in both women and men.
The addition of handgrip strength to an office-based risk score (age, sex, body mass index, systolic blood pressure, smoking and diabetes diagnosed) improved the prediction ability, based on C index change, for all-cause (p=0.013) and CV mortality (p=0.012) and incidence of CVD (p=0.009).
“These findings could have important public health implications, as grip strength in comparison with other physical measures, specifically cardiorespiratory fitness and physical activity, is easily measured, cheap and highly reproducible in clinical practice,” researchers said. [Age Ageing 2011;40:423-429]
“Grip strength may, therefore, be a useful method of identifying people with muscle weakness who are at high risk of a wide range of diseases and who might benefit from further health assessments of risk for vascular and nonvascular outcomes,” they added.
Researchers suggested the need for further work on the use of grip strength in risk scores or risk screening to establish its potential clinical utility.