Considerable controversy exists regarding the association between dietary calcium intake and risk of mortality from cardiovascular disease and all causes. Therefore, we performed a meta-analysis of prospective cohort studies to examine the controversy. We identified relevant studies by searching MEDLINE, Embase, and the Cochrane Library databases between 1 September 2013 and 30 December 2013. Reference lists of relevant articles were also reviewed. Observational prospective studies that reported relative risks and 95% confidence intervals for the association of calcium intake with cardiovascular and all-cause mortality were eligible. Study-specific relative risks were pooled using a random-effects model. In this meta-analysis, 11 prospective studies with 12 independent cohorts, involving 757,304 participants, were eligible. There was evidence of a non-linear association between dietary calcium intake and risk of mortality from cardiovascular disease (P for non-linearity <0.01) and all causes (P for non-linearity 900 mg/day) is not associated with a decreased risk of all-cause mortality.

Background: Previous studies have shown inconsistent findings regarding the association of light to moderate alcohol consumption with cause-specific mortality. Therefore, this study sought to examine the prospective association of alcohol consumption with all-cause and cause-specific mortality in the US population. Methods: This was a population-based cohort study of adults aged 18 years or older in the National Health Interview Survey (1997 to 2014) with linkage to the National Death Index records through December 31, 2019. Self-reported alcohol consumption was categorized into seven groups (lifetime abstainers; former infrequent or regular drinkers; and current infrequent, light, moderate, or heavy drinkers). The main outcome was all-cause and cause-specific mortality. Results: During an average follow-up of 12.65 years, among the 918,529 participants (mean age 46.1 years; 48.0% male), 141,512 adults died from all causes, 43,979 from cardiovascular disease (CVD), 33,222 from cancer, 8246 from chronic lower respiratory tract diseases, 5572 from accidents (unintentional injuries), 4776 from Alzheimer’s disease, 4845 from diabetes mellitus, 2815 from influenza and pneumonia, and 2692 from nephritis, nephrotic syndrome, or nephrosis. Compared with lifetime abstainers, current infrequent, light, or moderate drinkers were at a lower risk of mortality from all causes [infrequent—hazard ratio: 0.87; 95% confidence interval: 0.84 to 0.90; light: 0.77; 0.75 to 0.79; moderate 0.82; 0.80 to 0.85], CVD, chronic lower respiratory tract diseases, Alzheimer’s disease, and influenza and pneumonia. Also, light or moderate drinkers were associated with lower risk of mortality from diabetes mellitus and nephritis, nephrotic syndrome, or nephrosis. In contrast, heavy drinkers had a significantly higher risk of mortality from all causes, cancer, and accidents (unintentional injuries). Furthermore, binge drinking ≥ 1 day/week was associated with a higher risk of mortality from all causes (1.15; 1.09 to 1.22), cancer (1.22; 1.10 to 1.35), and accidents (unintentional injuries) (1.39; 1.11 to 1.74). Conclusions: Infrequent, light, and moderate alcohol consumption were inversely associated with mortality from all causes, CVD, chronic lower respiratory tract diseases, Alzheimer’s disease, and influenza and pneumonia. Light or moderate alcohol consumption might also have a beneficial effect on mortality from diabetes mellitus and nephritis, nephrotic syndrome, or nephrosis. However, heavy or binge had a higher risk of all-cause, cancer, and accidents (unintentional injuries) mortality.

Smoking remains a strong risk factor for premature death. This study examines the associations of nondaily smoking, daily smoking, and smoking cessation with the risks of mortality from all causes, cardiovascular disease, and cancer. This study used data from the National Health and Nutrition Examination Survey, a population-based, cross-sectional study. Data analysis was conducted in the U.S. from January to October 2020. Cox proportional hazard regression models were used to obtain adjusted hazard ratios. During 255,100 person-years of follow-up, 2,008 participants died (347 from cardiovascular diseases and 501 from cancer). A significant increase in the risk of all-cause mortality was observed for nondaily smokers (hazard ratio=1.50, 95% CI=1.08, 2.08) compared with that for those who had never smoked. For daily smokers, the adjusted hazard ratios for all-cause mortality were 1.54 (95% CI=1.24, 1.90) for those smoking <20 cigarettes per day, 2.09 (95% CI=1.65, 2.63) for those smoking 20-40 cigarettes per day, and 2.78 (95% CI=1.75, 4.43) for those smoking ≥40 cigarettes per day. An increased risk of cardiovascular disease and cancer mortality was also observed for daily smokers. Former smokers with ≥5 years since cessation had a lower risk of all-cause mortality than current smokers. This study suggests that nondaily smokers have a higher risk of all-cause mortality. The association of daily smoking with the risk of mortality increased as the number of cigarettes smoked per day increased. Among former smokers, the risk decreased with longer cessation. Tobacco control efforts should be targeted not only toward daily smokers but also toward nondaily smokers to reduce the risk of premature death owing to smoking.

Oxidative stress is a major risk factor in the onset and progression of type 2 diabetes mellitus (T2DM). NF-E2 related factor 2 (NRF2) is a pivotal transcription factor in oxidative stress related illnesses. This study included 2174 subjects with 879 cases of newly-diagnosed T2DM and 1295 healthy controls. Compared to individuals with the CC genotype, those with the AA genotype had lower total anti-oxidative capacity, superoxide dismutase, catalase, glutathione, glutathione peroxidase activity; and lower homeostasis model assessment of β-cell function index. Those with the AA genotype also had a higher malondialdehyde concentration and homeostasis model assessment of insulin resistance index values. The frequency of allele A was significantly higher in T2DM subjects (29.4%), compared to control subjects (26.1%; p = 0.019). Individuals with the AA genotype had a significantly higher risk of developing T2DM (OR 1.56; 95% CI 1.11, 2.20; p = 0.011), relative to those with the CC genotype, even after adjusting for known T2DM risk factors. Our results suggest that the NRF2 rs6721961 polymorphism was significantly associated with oxidative stress, anti-oxidative status, and risk of newly-diagnosed T2DM. This polymorphism may also contribute to impaired insulin secretory capacity and increased insulin resistance in a Chinese population.

Irisin is a newly discovered myokine, which is involved in energy metabolism and associated with "browning" of the white adipose tissue, obesity, diabetes mellitus and metabolic syndrome. It is still uncertain that whether irisin level is associated with coronary artery disease. The purpose of this study was to explore the relationship between irisin levels and coronary artery disease. A search of PubMed, MEDLINE, Elsevier Science Direct, Springer, Web of Science and China National Knowledge Infrastructure (CNKI) for studies published from 2000 to 2017 was undertaken to identify relevant studies. Case-control studies that reported the association between irisin levels and coronary artery disease were included. Methodological quality of the studies was assessed according to the Newcastle-Ottawa Scale. Random-efforts models were used to analyze the weighted mean difference (WMD) and its 95% confidence interval (CI). Subgroup analysis was performed to explore potential sources of heterogeneity. From 741 studies, 7 case-control studies involving 867 patients and 700 controls were selected for meta-analysis based on our inclusion and exclusion criteria. In these case-control studies, irisin concentrations were lower in coronary artery disease patients compared with healthy controls. In the meta-analysis, the pooled data indicated that irisin levels were -18.10 ng/mL ([95% CI: -35.53 to -0.68 ng/mL]; P<0.05) lower in patients with cardiovascular disease or atherosclerosis than healthy controls. This study confirmed that irisin levels were significantly lower in patients with coronary artery disease.