Resting heart rate and the risk of cardiovascular disease, total cancer, and all-cause mortality - A systematic review and dose-response meta-analysis of prospective studies.

BACKGROUND AND AIM: Epidemiological studies have reported increased risk of cardiovascular disease, cancer and all-cause mortality with greater resting heart rate, however, the evidence is not consistent. Differences by gender, adjustment for confounding factors, as well as the potential impact of subclinical disease are not clear. A previous meta-analysis missed a large number of studies, and data for atrial fibrillation have not been summarized before. We therefore aimed to clarify these associations in a systematic review and meta-analysis of prospective studies. METHODS AND RESULTS: PubMed and Embase were searched up to 29 March 2017. Summary RRs and 95% confidence intervals (CIs) were calculated using random effects models. Eighty seven studies were included. The summary RR per 10 beats per minute increase in resting heart rate was 1.07 (95% CI: 1.05-1.10, I2 = 61.9%, n = 31) for coronary heart disease, 1.09 (95% CI: 1.00-1.18, I2 = 62.3%, n = 5) for sudden cardiac death, 1.18 (95% CI: 1.10-1.27, I2 = 74.5%, n = 8) for heart failure, 0.97 (95% CI: 0.92-1.02, I2 = 91.4%, n = 9) for atrial fibrillation, 1.06 (95% CI: 1.02-1.10, I2 = 59.5%, n = 16) for total stroke, 1.15 (95% CI: 1.11-1.18, I2 = 84.3%, n = 35) for cardiovascular disease, 1.14 (95% CI: 1.06-1.23, I2 = 90.2%, n = 12) for total cancer, and 1.17 (95% CI: 1.14-1.19, I2 = 94.0%, n = 48) for all-cause mortality. There was a positive dose-response relationship for all outcomes except for atrial fibrillation for which there was a J-shaped association. CONCLUSION: This meta-analysis found an increased risk of coronary heart disease, sudden cardiac death, heart failure, atrial fibrillation, stroke, cardiovascular disease, total cancer and all-cause mortality with greater resting heart rate.

Effects of vitamin D supplementation on glycated haemoglobin and fasting glucose levels in hypertensive patients: a randomized controlled trial.

AIM: To investigate the efficacy of vitamin D supplementation on glycaemic control. METHODS: The Styrian Vitamin D Hypertension Trial was a single-centre, double-blind, placebo-controlled study conducted between 2011 and 2014 at the Medical University of Graz, Austria. We enrolled 200 people with arterial hypertension and 25-hydroxyvitamin D [25(OH)D] concentrations <30 ng/mL. Study participants were randomized to receive either 2800 IU of vitamin D or placebo per day for 8 weeks. The present study was a post hoc analysis that incorporated an analysis of covariance (ancova) approach, while adjusting for baseline differences. RESULTS: A total of 185 participants [mean ± standard deviation age, 60.1 ± 11.3 years; 47% women; mean 25(OH)D 21.2 ± 5.6 ng/mL, mean glycated haemoglobin (HbA1c) 44.8 ± 11.8 mmol/mol and mean body mass index 30.4 ± 5.4 kg/m(2) ] completed the trial. ancova showed a mean treatment effect [95% confidence interval (CI)] on HbA1c of -3.52 (-6.7 to -0.34) mmol/mol (p = .045). There was no difference in fasting glucose -4.7 mg/dL (95% CI -16.3 to 6.9; p = .426). CONCLUSIONS: Vitamin D supplementation in obese hypertensive patients with low 25(OH)D reduces HbA1c levels. This finding warrants further investigation into potential vitamin D effects on glucose homeostasis.

Resting heart rate and the risk of type 2 diabetes: A systematic review and dose--response meta-analysis of cohort studies.

BACKGROUND: High resting heart rate has been associated with increased risk of type 2 diabetes in several studies, but the available data are not consistent and it is unclear if there is a dose-response relationship between resting heart rate and type 2 diabetes risk. We aimed to clarify this association by conducting a systematic review and meta-analysis of published studies. METHODS AND RESULTS: PubMed, Embase and Ovid Medline databases were searched for prospective studies published up until October 11th, 2013. Summary relative risks were estimated using a random effects model. Ten cohort studies with >5628 cases and 119,915 participants were included. The summary RR for high vs. low resting heart rate was 1.83 (95% CI: 1.28-2.60, I(2) = 88%, n = 7), and in the dose-response analysis the summary RR was 1.20 (95% CI: 1.07-1.34, I(2) = 93%, n = 9) for an increase of 10 beats per minute. The heterogeneity was to a large degree explained by two studies. There was evidence of nonlinear associations between resting heart rate (pnonlinearity < 0.0001) and risk of type 2 diabetes. CONCLUSION: The current meta-analysis indicates a strong positive association between high resting heart rate and the risk of type 2 diabetes. As a non-invasive marker of type 2 diabetes risk, resting heart rate may have potential in the clinical setting, especially for interventions aimed at lowering the risk of type 2 diabetes. Additional studies are needed to clarify the mechanisms that may be responsible for the assoiation between resting heart rate and type 2 diabetes.