Sarcopenia Related to Human Immunodeficiency Virus: Protective Effects of Exercise

Validity of equations for estimating fat-free mass in people living with the human immunodeficiency virus

BACKGROUND & AIMS

Equations estimating fat-free mass (FFM) in people living with the human immunodeficiency virus (HIV) show differences in the validation process. The current study aimed to verify the validity of FFM estimation equations derived from bioelectrical impedance (BIA) in people living with HIV aged 40 years and older.

METHODS

A cross-sectional study was conducted with 68 participants evaluated using dual-energy X-ray absorptiometry (DXA) and by two BIA devices (Analyzer and Biodynamics). The study aimed to determine the validity of six different FFM equations from four different studies by Lukaski and Bolonchuk (1987), Kotler et al. (1996), Beraldo et al. (2015) and Hegelund et al. (2017). Comparisons were made using the t-test or Wilcoxon test. To verify the validity between DXA and two BIA devices, the following statistical analyses were performed: Lin's concordance correlation coefficient, intraclass correlation coefficient, coefficient of determination, standard error of the estimate, differences in the limits of agreement by Bland and Altman analysis, correlation between the average and the differences of the methods by Pearson or Spearman correlation.

RESULTS

Only equation 2 of Kotler et al. (1996) for males by Biodynamics BIA showed no difference in FFM. The Lin's concordance correlation coefficient was excellent (0.96), irrespective of sex, for Equation 2 of Kotler et al. (1996) by BIA Analyzer. All equations were reproducible (>0.85). The coefficient of determination ranged from 68% to 92%, and the standard error of the estimates ranged from 1.8 kg to 5.0 kg. The differences between the limits of agreement ranged from 7.2 kg to 14.9 kg, and the correlations between the average and the differences of the methods showed differences in FFM for three equations (p < 0.01).

CONCLUSION

The choice of equations must consider the equipment used and the sex of the sample investigated. Only Equation 2 of Kotler et al. (1996) was considered valid, irrespective of sex, to estimate the FFM by BIA Analyzer.

Statin protects men but not women with HIV against loss of muscle mass, strength, and physical function: a pilot study

Statins are cholesterol-lowering drugs commonly used among people with HIV, associated with an increased risk of myopathies. Considering that cardiovascular disease, statin therapy, and sarcopenia are independently prevalent in people with HIV, clarity on the potential benefits or harms of statin therapy on muscle health is useful to provide insight into ways to maximize skeletal muscle health and minimize CVD risk in this population. We aimed to study the effects of statin therapy on strength, muscle mass, and physical function parameters in people with HIV. This was a pilot cross-sectional study. People with HIV on continuous statin therapy (n = 52) were paired 1:1 according to age (people with HIV 53.9 ± 8.2 and people with HIV on statins 53.9 ± 8.4 years), sex, body mass index (Body mass index, people with HIV 28.6 ± 5.3 and people with HIV on statins 28.8 ± 6.3 kg/m²), and race with people with HIV not using statin (n = 52). Participants were evaluated for muscle strength (i.e. handgrip strength), lean and fat body mass (using bioelectric impedance analysis), and physical function (i.e. Short Physical Performance Battery-SPPB). Isokinetic strength and appendicular lean mass (using dual-energy X-ray absorptiometry), more accurate strength and body composition measures, were determined in 38% of the participants. Overall, statin usage does not exacerbated loss of muscle strength (32.2 ± 11.5 vs. 30.3 ± 9.6 kg, p > 0.05) muscle mass (7.6 ± 1.8 vs. 7.7 ± 1.1 kg/m², p > 0.05), and impaired physical performance (10.1 ± 1.8 vs. 9.7 ± 2.1 points, p > 0.05) of PLWH. When analyzed by sex, men living with HIV on statins usage presented higher appendicular muscle mass (28.4 ± 3.1 vs. 26.2 ± 4.9 kg, p < 0.05) handgrip strength (42.1 ± 8.8 vs. 37.1 ± 8.3 kg, p < 0.05) and physical function through SPPB score (10.9 ± 1.3 vs. 9.5 ± 2.1, p < 0.05) than men living with HIV not on statins treatment. The same protection was not observed in women. This data was demonstrated when muscle mass and strength were determined clinically (i.e. handgrip strength and electrical impedance) and when more precise laboratory measurements of muscle mass and strength were conducted (i.e. isokinetic strength and DXA scans). Statin does not exacerbate muscle wasting, strength loss, or muscle dysfunction among people with HIV. Indeed, statins may protect men, but not woman with HIV against HIV and antiretroviral therapy-induced loss of muscle mass and strength.

Sarcopenia in people living with HIV in Hong Kong: which definition correlates with health outcomes?

Introduction

Sarcopenia is an important clinical syndrome in older people living with HIV (PLWH). With a change to the Asia sarcopenia definition in 2019, we aimed to determine whether health outcomes were associated with different definitions of sarcopenia among Asian PLWH.

Methods

We performed a prospective cross‐sectional study enrolling PLWH aged ≥35 years from January 2018 to November 2021. We defined sarcopenia by the Asia Working Group of Sarcopenia (AWGS) criteria in 2014 and 2019. AWGS‐2014 included low muscle mass plus weak handgrip strength and/or slow gait speed. AWGS‐2019 included low muscle mass plus low muscle strength or physical performance, while the presence of all defines severe sarcopenia. We measured appendicular skeletal muscle mass using dual‐energy X‐ray absorptiometry, handgrip strength, usual gait speed, five‐time chair stand test and Short Physical Performance Battery. Correlations between each sarcopenia definition and health‐related quality of life (using EQ‐5D‐5L and SF‐36) and functional disability were determined.

Results

One hundred and fifty Asian PLWH were enrolled, 132 (88%) were male, mean age was 60±10 years, duration of HIV diagnosis was 13 (IQR 8–18) years and current CD4 count was 574 (IQR 362–762) cells/mm³, 67 (45%) had multimorbidity, 64 (43%) had polypharmacy. Prevalence of sarcopenia by AWGS‐2014, AWGS‐2019 and severe sarcopenia was 17.3%, 27.3% and 18.0%, respectively. Age, education and polypharmacy were associated with sarcopenia. Sarcopenia (AWGS‐2014) and severe sarcopenia were associated with mobility, physical functioning and physical component score (SF‐36). All three criteria were associated with impaired instrumental activities of daily living (IADL). After age and sex adjustment, sarcopenia (AWGS‐2014) (adjusted odds ratio/aOR 5.4, 95% confidence interval/CI 2.0–15.1) and severe sarcopenia (aOR 5.1, 95% CI 1.9–14.0) were associated with mobility and physical component score (SF‐36) (β coefficients –5.3342, p = 0.022 and –5.412, p = 0.019). Sarcopenia (AWGS 2014) (aOR 5.2, 95% CI 1.7–16.2), sarcopenia (AWGS‐2019) (aOR 4.5, 95% CI 1.5–13.1) and severe sarcopenia (aOR 3.5, 95% CI 1.1–10.9) were associated with impaired IADL in fully adjusted models.

Conclusions

In a sample of Asian PLWH, 17.3%, 27.3% and 18.0% had sarcopenia as defined by AWGS‐2014, AWGS‐2019 and severe sarcopenia, respectively. Sarcopenia by AWGS‐2014 and severe sarcopenia correlated with parameters of poor health outcomes, while sarcopenia by AWGS‐2019 correlated with functional disability.

Rehabilitation of Older Adults with Sarcopenia: From Cell to Functioning

The 20th and 21st centuries have witnessed a substantial increase in human life expectancy and in the number of men and women aged 60 years and older. Aging is associated with a large number of health conditions, including sarcopenia, which has been the subject of important research in the past 30 years. Sarcopenia is characterized by an age-related loss of muscle mass, weakness, and impaired physical performance. The condition can be diagnosed with a combination of measurements of these three elements. The precise definition of sarcopenia and the selection of optimal assessment methods have changed significantly in the past 20 years; nonetheless, the prevalence of sarcopenia in the general older population is in the range of 5–15%. Molecular and cellular events at the muscle cell level impact the size and quality of muscles (force adjusted for size). The active and passive mechanical properties of single muscle fibers are altered by changes in the structure and function of various cellular elements. Systemic factors such as inflammation, loss of hormonal influence, and deleterious lifestyle choices also contribute to sarcopenia. The consequences of sarcopenia include many adverse effects such as impairments in activities of daily living, falls, loss of independence, and increased mortality. Several rehabilitative interventions have been tested, and the safest and most effective is the use of progressive resistance exercise. An increase in dietary protein intake has synergistic effects. Future research should focus on a consensus definition of sarcopenia, identification of the best assessment methods, understanding of biological mechanisms, and testing of innovative interventions.