Sarcopenia is a progressive loss of muscle mass, strength, and function and is associated with an increased risk of death, falls, disability, hospitalization, and frailty. Cardiovascular diseases and sarcopenia involve various interrelated mechanisms. Sedentary behavior and malnutrition in patients with cardiovascular diseases, especially heart failure, can lead to decreased muscle mass and function, which accelerates low physical activity and eventually exacerbates dyspnea and fatigue.

Previous studies have shown that, among older patients with hypertension, patients with comorbid sarcopenia exhibit higher mortality compared with those with hypertension alone. The present study by Inoue et al. investigated the prognostic significance of handgrip strength and body mass index (BMI) in hypertensive older patients (https://doi.org/10.1038/s41440-024-01921-2). The results demonstrated that patients with low handgrip strength combined with low BMI < 22 kg/m2 exhibited high mortality (adjusted hazard ratio: 4.55; 95% confidence interval: 1.33–18.13).

Lifestyle modification, including physical activity, exercise, losing weight, cessation of smoking, lowering alcohol intake, and reduction of salt, is considered the first-line therapy for hypertension. Among these lifestyle modifications, losing weight is controversial in the older population because of the obesity paradox, in which mortality is reduced in overweight patients. A systematic review reported the existence of the obesity paradox in individuals aged > 65 years old, especially among those with comorbidities or acute medical conditions [1]. The obesity paradox has also been observed in hypertensive patients. In a study conducted in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) cohort of hypertensive patients without diabetes mellitus or manifest cardiovascular disease at entry, obesity was found to be associated with lower all-cause mortality [2]. The present study is consistent with previous studies reporting that, among older people, mortality was higher among those with lower BMI. However, BMI alone does not provide information about body composition or the difference between visceral fat and subcutaneous fat. The aging process is characterized by an increase in body total fat mass and a concomitant decrease in lean mass and bone density, which cannot be measured by BMI. Alteration of body composition is one of the causes of differences in previous results regarding the relationship between BMI and mortality, which has been reported to vary between different age groups [3]. In the present study, mortality risk did not significantly differ between individuals with 22 kg/m2 ≤ BMI < 25 kg/m2 and those with BMI ≥ 25 kg/m2 (https://doi.org/10.1038/s41440-024-01921-2). In a prior study, a J‐shaped relationship between BMI and mortality was reported in large cohorts [4]. Therefore, for participants that do not have a low BMI (<22 kg/m2), measuring BMI alone cannot distinguish differences in mortality risk. The quantity of muscle mass or quality of muscle explained by composition, fat filtration, and fibrosis may provide useful information for stratifying these patients.

Investigating the mortality of older hypertensive patients using both BMI and muscle function is considered to be a reasonable approach [5], as reported in the current study. Another study by Wang et al. evaluated hand grip strength and all-cause mortality in older hypertensive patients. They examined the hand grip strength and medical condition of 2,990 hypertensive participants aged ≥ 60 years. The hazard ratio (95% confidence interval) for all-cause mortality in the highest grip strength tertile was 0.266 (0.168–0.419), compared with the lowest grip strength tertile [6]. Handgrip strength is a simple and inexpensive method for measuring muscle strength, which can be used to stratify cardiovascular event risk and mortality [7]. Prediction ability improves by adding handgrip strength to other cardiovascular risk factors such as age, smoking, BMI, and systolic blood pressure [8].

Importantly, in the current study by Inoue et al., diastolic blood pressure was significantly lower in patients with BMI < 22 kg/m2 compared with patients with BMI ≥ 22 kg/m2. In frail older people, reduced blood pressure is associated with mortality; this phenomenon is related to the decline in blood pressure that begins several years before death, known as reverse causality [9]. Regarding sarcopenia, several studies have reported an interrelationship between sarcopenia and hypertension via the underlying mechanisms of insulin resistance, chronic inflammation, metabolic imbalance, and aging. Arterial stiffness has been suggested to be associated with handgrip strength by affecting pulse pressure [10]. The blood pressure determinants associated with BMI, handgrip strength, appendicular muscle mass, and sarcopenia should be investigated in future research. The population examined in the present study comprised older individuals with a median age of 77 years, and the prevalence of frailty was relatively high (40%). Sarcopenia and frailty often coexist, and these patients are susceptible to adverse health outcomes. It is recommended that management of blood pressure and weight control are personalized for frail patients. In a post-hoc analysis in the Systolic Blood Pressure Intervention Trial (SPRINT), intensive blood pressure was found to benefit patients with frailty or sarcopenia without increasing serious adverse events [11, 12]. It remains to be clarified whether similar benefits exist for people who require care, and nursing home residents.

It may be useful for future studies to investigate whether improvement of muscle strength, measured by handgrip strength, decreases mortality in hypertensive older patients. Moreover, in addition to BMI, body composition may provide useful insights for the development of approaches for disease protection and prevention.