The aim of this meta-analysis is to comprehensively evaluate the effects of lean mass on all-cause mortality across different cancer types. This is a meta-analysis. Cohort studies on lean mass and mortality published before December 20, 2017 were obtained by systematic search on PubMed, Cochrane Library, and Embase. Inclusion criteria were cohort studies reporting lean mass measurements by dual-energy X-ray absorptiometry, bioimpedance analysis or computed tomography, and with all-cause mortality as the study outcome. Exclusion criteria were studies using muscle mass surrogates, anthropometric measurement of muscle, rate of change in muscle mass, and sarcopenia defined by composite criteria. Hazard ratios (HRs) and 95% confidence intervals (CIs) of low/reduced lean mass on cancer mortality were pooled with a random-effects model. Subgroup analysis stratifying studies according to cancer type and measurement index was performed. Altogether 100 studies evaluated the association between lean mass and cancer mortality. The overall pooled HR on cancer mortality was 1.41 (95% CI, 1.24 to 1.59) for every standard deviation decrease in lean mass and 1.69 (95% CI, 1.56 to 1.83) for patients with sarcopenia (binary cutoffs). Overall mortality was also significantly associated with sarcopenia in across various cancer types, except for hematopoietic, breast, ovarian and endometrial, and prostate cancer. The robust association of decreased lean mass with increased mortality further justified the importance of developing clinical guidelines for managing sarcopenia in cancer patients. Public health initiatives aiming at promoting awareness of muscle health in susceptible individuals are urgently needed.

Sarcopenia is recognized to be a health problem which is as serious as obesity, but its relevance to mortality is unclear. We conducted a meta-analysis of cohort studies on lean mass and mortality in populations with different health conditions. In this study, a systematic search of PubMed, Cochrane Library and Embase was performed for cohort studies published before Dec 20, 2017 which examined the relationship between lean mass and mortality. We included studies reporting lean mass measurement by dual-energy X-ray absorptiometry, bioimpedance analysis or computed tomography, as continuous (per standard deviation [SD] decrease) or binary variables (using sarcopenia cutoffs). We excluded studies which used muscle mass surrogates, anthropometric measurement of muscle, rate of change in muscle mass, and sarcopenia defined by composite criteria. The primary study outcome was all-cause mortality. Pooled hazard ratio estimates were calculated using a random effects model. A total of 9602 articles were identified from the systematic search, and 188 studies with 98 468 participants from 34 countries were included in the meta-analysis. Of the 68 studies included in the present meta-analysis, the pooled HR was 1.36 and 1.74 for every SD decrease in lean mass and in people with low lean mass (cutoffs), respectively. Significant associations were also observed in elderly and all disease subgroups, irrespective of the measurement modalities. Lower lean mass is robustly associated with increased mortality, regardless of health conditions and lean mass measurement modalities. This meta-analysis highlighted low lean mass as a key public health issue.

Phytosterols found naturally in plants are known to reduce cholesterol absorption in the gut. The traditional southern Chinese diet typically contains many vegetables and not much meat, and there is high prevalence of lactose intolerance in Chinese; we therefore aimed to test if phytosterols-enriched milk is effective in lowering serum LDL-cholesterol in Chinese. Two hundred and twenty-one participants (41 men and 180 women; age 24–79) without cholesterol-lowering drugs or diabetes mellitus were randomized to daily intake of phytosterols-enriched low-fat milk which contained 1.5 g phytosterols per day (N = 110) or a conventional low-fat milk (N = 111) for three weeks. Fasting bloods were taken before and at the end of the study for the measurement of lipid and glucose profile. Physical examination was also performed. Comparing treatment with control, treatment group had significant decrease in serum LDL-cholesterol level (9.5 ± 2.0%; p < 0.0001). Phytosterols intake also decreased total cholesterol (P < 0.0001) and diastolic blood pressure (P = 0.01). Consumption of a phytosterols-enriched low-fat milk led to a significant fall in LDL-cholesterol, total cholesterol, and diastolic blood pressure in Chinese. This can be recommended as part of a healthy diet for people. (ClinicalTrials.gov identifier: NCT02541201; Date of registration: 26 Aug 2015).

Sarcopenia has been an emerging theme in clinical oncology. Various definitions of sarcopenia have been proposed, but their prognostic performance have yet to be evaluated and compared. The aim of this meta-analysis is to comprehensively evaluate the performance of different cutoff definitions of sarcopenia in cancer mortality prognostication. This is a meta-analysis. Cohort studies on lean mass and mortality published before December 20, 2017 were obtained by systematic search on PubMed, Cochrane Library, and Embase. Inclusion criteria were cohort studies reporting binary lean mass categorized according to clearly defined cutoffs, and with all-cause mortality as study outcome. Studies were stratified according to the cutoff(s) used in defining low lean mass. The cutoff-specific hazard ratios (HRs) and 95% confidence intervals (CIs) of low lean mass on cancer mortality were pooled with a random-effects model and compared. Altogether 81 studies that studied binary lean mass were included. The pooled HRs on cancer mortality using the 3 most used definitions were: 1.74 (95% CI, 1.46–2.07) using the definition proposed by International Consensus of Cancer Cachexia, 1.45 (95% CI, 1.21–1.75) using that by Martin, and 1.58 (95% CI, 1.35–1.84) using that by Prado. The associations between sarcopenia and cancer mortality using other definitions were all statistically significant, despite different estimates were observed. The association of low lean mass with increased mortality was consistent across different definitions; this provides further evidence on the poorer survival in cancer patients with sarcopenia. However, further studies evaluating the performance of each definition are warranted.

Lean mass is commonly measured by 3 modalities, dual energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), and computerized tomography (CT). CT is considered the most accurate, while lean mass measured by DXA and BIA often consists of non-muscle compartment, and hence considered less accurate when compared with CT. It remains unclear if the association of lean mass with mortality would differ using different measurement modalities. A systematic review and meta-analysis of lean mass and mortality was conducted. The analysis was stratified by different measurement modalities and health conditions. Pooled hazard ratios were estimated using a random effects model. This meta-analysis included 188 studies with 98 468 participants. Reduced lean mass measured by BIA, DXA, and CT, was associated with increased risk of mortality with a hazard ratio (HR) of 1.35 (95% CI, 1.21–1.49), 1.18 (95% CI, 1.06–1.30), and 1.44 (95% CI, 1.32–1.57), respectively. Similarly, low lean mass defined by BIA-, DXA-, and CT-measurement was associated with increased risk of mortality, with an HR of 1.81 (95% CI, 1.56–2.10), 1.44 (95% CI, 1.29–1.60), and 1.78 (95% CI, 1.64–1.93). Reduced and low lean mass were robustly associated with increased mortality in studies using different measurement modalities.

Muscle mass is one of the key components in defining sarcopenia and is known to be important for locomotion and body homeostasis. Lean mass is commonly used as a surrogate of muscle mass and has been shown to be associated with increased mortality. However, the relationship of lean mass with mortality may be affected by different clinical conditions, modalities used, cut-off point to define low or normal lean mass, and even types of cancer among cancer patients. Thus, we aim to perform a comprehensive meta-analysis of lean mass with mortality by considering all these factors. Systematic search was done in PubMed, Cochrane Library and Embase for articles related to lean mass and mortality. Lean mass measured by dual X-ray absorptiometry, bioelectrical impedance analysis, and computerized tomography were included. The number of relevant studies has increased continuously since 2002. A total of 188 studies with 98 468 people were included in the meta-analysis. The association of lean mass with mortality was most studied in cancer patients, followed by people with renal diseases, liver diseases, elderly, people with cardiovascular disease, lung diseases, and other diseases. The meta-analysis can be further conducted in subgroups based on measurement modalities, site of measurements, definition of low lean mass adopted, and types of cancer for studies conducted in cancer patients. This series of meta-analysis provided insight and evidence on the relationship between lean mass and mortality in all directions, which may be useful for further study and guideline development.