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Grip Strength Fades Faster With Age in Men With Than Without HIV
 
 
  6th International Workshop on HIV and Aging
 
October 5-6, 2015, Washington, DC
 
Mark Mascolini
 
Grip strength, a component of the standard frailty phenotype, declined faster in men with than without HIV in a 7-year study of more than 1500 HIV-positive and negative men who have sex with men (MSM) in the Multicenter AIDS Cohort Study (MACS) [1]. Compared with HIV-negative men, HIV-positive men had a 71% greater risk of clinically weak grip strength.
 
MACS investigators undertook this study in the belief that "grip strength in persons aging with HIV may provide an important method of gauging health and longevity in this population." They noted that grip strength predicts functional decline, disability, and death. Some propose that grip strength could be a marker of biological aging. Published research disagrees on whether grip strength correlates well with physical function in people with HIV infection [2,3]. The MACS grip strength analysis aimed to compare this measure over time in men with and without HIV.
 
The researchers defined grip strength as the average of three tries in the dominant hand; clinically weak grip strength meant less than 26 kg of force. To explore associations between age and grip strength, the MACS team used generalized estimating equations adjusted for HIV status, age, height, weight, race, education, smoking, drug and alcohol use, diabetes, hypertension, arthritis, depression, and hepatitis B or C infection. A model just for men with HIV included nadir CD4 count, undetectable viral load, and history of clinical AIDS. The researchers used time-to-event Cox proportional hazard models to estimate the risk of developing clinically weak grip strength.
 
The study involved 716 MSM with HIV and 836 without HIV, all at least 50 years old and evaluated at a MACS visit twice or more from October 2007 through September 2014. They averaged 10 grip strength assessments (range 2 to 18). Men with HIV averaged 53.4 years in age at their baseline visit, compared with 56.0 in the HIV-negative group (P < 0.001). Men with HIV had significantly lower body mass index (average 25.6 versus 27.2 kg/m2, P < 0.001), a higher proportion of nonwhites (34.5% versus 20.7%, P < 0.001), a higher proportion with a drug use history (50.6% versus 39.8%, P< 0.001), and higher proportions with liver disease and HBV or HCV infection.
 
At age 50 grip strength averaged 37.9 kg in men with HIV versus 38.2 kg in HIV-negative men, a nonsignificant difference (P = 0.7). A fully adjusted model determined that grip strength fell by 0.33 kg with each year of age (P < 0.001). Grip strength fell 0.10 kg per year more in men with than without HIV (P = 0.005).
 
In analyses limited to men with HIV, a history of AIDS heightened the risk of declining grip strength, but viral load and nadir CD4 count did not. Neither did use of d-nucleosides, zidovudine, or efavirenz.
 
The fully adjusted Cox proportional hazard model determined that men with HIV had a 71% greater risk of clinically weak grip strength than men without HIV (adjusted hazard ratio 1.71, 95% confidence interval 1.22 to 2.40).
 
The MACS investigators suggested that waning grip strength "may represent an important underlying contributor to the increased risk of frailty that has been well documented in those aging with HIV." As HIV-positive people age, they added, declining strength "may contribute to decreased active life expectancy and lower quality of life."
 
References
 
1. Schrack JA, Althoff KN, Jacobson LP, et al. Aging-related strength decline is accelerated in HIV-infected men. 6th International Workshop on HIV and Aging. October 5-6, 2015, Washington, DC. Abstract 22.
 
2. Raso V, Shephard RJ, do Rosario Casseb JS, da Silva Duarte AJ, D'Andrea Greve JM. Handgrip force offers a measure of physical function in individuals living with HIV/AIDS. J Acquir Immune Defic Syndr. 2013;63:e30-e32.
 
3. Richert L, Brault M, Mercie P, et al. Handgrip strength is only weakly correlated with physical function in well-controlled HIV infection: ANRS CO3 Aquitaine Cohort. J Acquir Immune Defic Syndr. 2014;65:e25-e27.