Vitamin D and calcium may affect the cardiovascular system independently and interactively.
To assess whether vitamin D and calcium supplements reduce the risk for cardiovascular events in adults.
...Studies published in English from 1966 to July 2009 in MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials.
Two investigators independently selected 17 prospective studies and randomized trials that examined vitamin D supplementation, calcium supplementation, or both and subsequent cardiovascular events.
Three investigators extracted and checked data about study designs, participants, exposures or interventions, outcomes, and data quality.
Five prospective studies of patients receiving dialysis and 1 study involving a general population showed consistent reductions in cardiovascular disease (CVD) mortality among adults who received vitamin D supplements. Four prospective studies of initially healthy persons found no differences in incidence of CVD between calcium supplement recipients and nonrecipients. Results of secondary analyses in 8 randomized trials showed a slight but statistically nonsignificant reduction in CVD risk (pooled relative risk, 0.90 95% CI, 0.77 to 1.05) with vitamin D supplementation at moderate to high doses (approximately 1000 IU/d) but not with calcium supplementation (pooled relative risk, 1.14 CI, 0.92 to 1.41), or a combination of vitamin D and calcium supplementation (pooled relative risk, 1.04 CI, 0.92 to 1.18) compared with placebo.
Only articles published in English that reported cardiovascular event outcomes were included. The small number of studies, the lack of trials designed specifically to assess primary effects on cardiovascular outcomes, and important between-study heterogeneity preclude definitive conclusions.
Evidence from limited data suggests that vitamin D supplements at moderate to high doses may reduce CVD risk, whereas calcium supplements seem to have minimal cardiovascular effects. Further research is needed to elucidate the role of these supplements in CVD prevention.
The American Heart Association and the National Heart, Lung, and Blood Institute.
Abstract Background Cardiovascular risk is inconsistent in the normal-weight, overweight, and obese individuals due to metabolic abnormality. We aimed to investigate combined effects of obesity and ...metabolic abnormality on the risk of cardiovascular disease and mortality. Methods The MEDLINE, EMBASE, Cochrane library, and references of relevant original articles prior to May 2013 were searched for prospective studies investigating cardiovascular risk and death associated with combined effects of obesity and metabolic syndrome or insulin resistance. Pooled relative risks (RR) and 95% confidence intervals (CI) were calculated using random-effects or fixed-effect models when appropriate. Results Fourteen perspective studies with a total of 299,059 participants and 12,125 cases of incident CVD, 2130 cases of CVD death, and 7071 cases of all-cause death were included in the meta-analysis. Compared with healthy normal-weight individuals, metabolically healthy overweight (MHOW) and obese (MHOB) individuals showed increased risk for CVD events, which appeared much stronger during the long-term follow-up period of > 15 years, with pooled RR of 1.47 (95% CI 1.37–1.58) in MHOW and 2.00 (95% CI 1.79–2.24) in MHOB. Normal-weight but metabolically abnormal individuals were at increased risk for CVD (pooled RR 1.81, 95% CI 1.56–2.10), CVD-related death (pooled RR 1.55, 95% CI 1.16–2.08), and all-cause death (pooled RR 1.27, 95% CI 1.10–1.47). Metabolically abnormal obese individuals were at the highest risk for CVD and mortality. Conclusion Individuals with metabolic abnormality, although at normal-weight, had an increased risk of CVD and mortality. Healthy overweight and obese persons had higher risk, which refuted the notion that metabolically healthy obese phenotype is a benign condition.
We aimed to evaluate the effects of the COVID-19 lock down on lifestyle in China during the initial stage of the pandemic. A questionnaire was distributed to Chinese adults living in 31 provinces of ...China via the internet using a snowball sampling strategy. Information on 7-day physical activity recall, screen time, and emotional state were collected between January 24 and February 2, 2020. ANOVA, χ² test, and Spearman's correlation coefficients were used for statistical analysis. 12,107 participants aged 18-80 years were included. During the initial phase of the COVID-19 outbreak, nearly 60% of Chinese adults had inadequate physical activity (95% CI 56.6%-58.3%), which was more than twice the global prevalence (27.5%, 25.0%-32.2%). Their mean screen time was more than 4 hours per day while staying at home (261.3 ± 189.8 min per day), and the longest screen time was found in young adults (305.6 ± 217.5 min per day). We found a positive and significant correlation between provincial proportions of confirmed COVID-19 cases and negative affect scores (r = 0.501,
= 0.004). Individuals with vigorous physical activity appeared to have a better emotional state and less screen time than those with light physical activity. During this nationwide lockdown, more than half of Chinese adults temporarily adopted a sedentary lifestyle with insufficient physical activity, more screen time, and poor emotional state, which may carry considerable health risks. Promotion of home-based self-exercise can potentially help improve health and wellness.
Abstract Objective We aimed to systematically review available literature linking adipokines to gestational diabetes mellitus (GDM) for a comprehensive understanding of the roles of adipokines in the ...development of GDM. Methods We searched PubMed/MEDLINE and EMBASE databases for published studies on adipokines and GDM through October 21, 2014. We included articles if they had a prospective study design (i.e., blood samples for adipokines measurement were collected before GDM diagnosis). Random-effects models were used to pool the weighted mean differences comparing levels of adipokines between GDM cases and non-GDM controls. Results Of 1523 potentially relevant articles, we included 25 prospective studies relating adipokines to incident GDM. Our meta-analysis of nine prospective studies on adiponectin and eight prospective studies on leptin indicated that adiponectin levels in the first or early second trimester of pregnancy were 2.25 μg/ml lower (95% CI: 1.75–2.75), whereas leptin levels were 7.25 ng/ml higher (95% CI 3.27–11.22), among women who later developed GDM than women who did not. Prospective data were sparse and findings were inconsistent for visfatin, retinol binding protein (RBP-4), resistin, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and vaspin. We did not identify prospective studies for several novel adipokines, including chemerin, apelin, omentin, or adipocyte fatty acid-binding protein. Moreover, no published prospective studies with longitudinal assessment of adipokines and incident GDM were identified. Conclusion Adiponectin levels in the first or second trimester of pregnancy are lower among pregnant women who later develop GDM than non-GDM women, whereas leptin levels are higher. Well-designed prospective studies with longitudinal assessment of adipokines during pregnancy are needed to understand the trajectories and dynamic associations of adipokines with GDM risk.
The relationship between dietary glycemic index, glycemic load and risk of coronary heart disease (CHD), stroke, and stroke-related mortality is inconsistent.
We systematically searched the MEDLINE, ...EMBASE, and Science Citation Index Expanded databases using glycemic index, glycemic load, and cardiovascular disease and reference lists of retrieved articles up to April 30, 2012. We included prospective studies with glycemic index and glycemic load as the exposure and incidence of fatal and nonfatal CHD, stroke, and stroke-related mortality as the outcome variable. Pooled relative risks (RR) and 95% confidence intervals (CI) were calculated using random-effects models.
Fifteen prospective studies with a total of 438,073 participants and 9,424 CHD cases, 2,123 stroke cases, and 342 deaths from stroke were included in the meta-analysis. Gender significantly modified the effects of glycemic index and glycemic load on CHD risk, and high glycemic load level was associated with higher risk of CHD in women (RR=1.49, 95%CI 1.27-1.73), but not in men (RR=1.08, 95%CI 0.91-1.27). Stratified meta-analysis by body mass index indicated that among overweight and obese subjects, dietary glycemic load level were associated with increased risk of CHD (RR=1.49, 95%CI 1.27-1.76; P for interaction=0.003). Higher dietary glycemic load, but not glycemic index, was positively associated with stroke (RR=1.19, 95% CI 1.00-1.43). There is a linear dose-response relationship between dietary glycemic load and increased risk of CHD, with pooled RR of 1.05 (95%CI 1.02-1.08) per 50-unit increment in glycemic load level.
High dietary glycemic load is associated with a higher risk of CHD and stroke, and there is a linear dose-response relationship between glycemic load and CHD risk. Dietary glycemic index is slightly associated with risk of CHD, but not with stroke and stroke-related death. Further studies are needed to verify the effects of gender and body weight on cardiovascular diseases.
To quantitatively assess the strength and shape of the association between blood 25-hydroxy vitamin D 25(OH)D levels and incident risk of type 2 diabetes.
A systematic search of the MEDLINE and ...Embase databases and a hand search of references from original reports were conducted up to 31 October 2012. Prospective observational studies that assessed the association between blood levels of 25(OH)D and risk of incident type 2 diabetes were included for meta-analysis. DerSimonian and Laird's random-effects model was used. A quadratic spline regression analysis was used to examine the shape of the association with a generalized least-squares trend test performed for the dose-response relation.
A total of 21 prospective studies involving 76,220 participants and 4,996 incident type 2 diabetes cases were included for meta-analysis. Comparing the highest to the lowest category of 25(OH)D levels, the summary relative risk for type 2 diabetes was 0.62 (95% CI 0.54-0.70). A spline regression model showed that higher 25(OH)D levels were monotonically associated with a lower diabetes risk. This inverse association did not differ by sex, duration of follow-up, study sample size, diabetes diagnostic criteria, or 25(OH)D assay method. A linear trend analysis showed that each 10 nmol/L increment in 25(OH)D levels was associated with a 4% lower risk of type 2 diabetes (95% CI 3-6; P for linear trend < 0.0001).
Our meta-analysis showed an inverse and significant association between circulating 25(OH)D levels and risk of type 2 diabetes across a broad range of blood 25(OH)D levels in diverse populations.
Guidelines recommend exercise for cardiovascular health, although evidence from trials linking exercise to cardiovascular health through intermediate biomarkers remains inconsistent. We performed a ...meta-analysis of randomized controlled trials to quantify the impact of exercise on cardiorespiratory fitness and a variety of conventional and novel cardiometabolic biomarkers in adults without cardiovascular disease.
Two researchers selected 160 randomized controlled trials (7487 participants) based on literature searches of Medline, Embase, and Cochrane Central (January 1965 to March 2014). Data were extracted using a standardized protocol. A random-effects meta-analysis and systematic review was conducted to evaluate the effects of exercise interventions on cardiorespiratory fitness and circulating biomarkers. Exercise significantly raised absolute and relative cardiorespiratory fitness. Lipid profiles were improved in exercise groups, with lower levels of triglycerides and higher levels of high-density lipoprotein cholesterol and apolipoprotein A1. Lower levels of fasting insulin, homeostatic model assessment-insulin resistance, and glycosylated hemoglobin A1c were found in exercise groups. Compared with controls, exercise groups had higher levels of interleukin-18 and lower levels of leptin, fibrinogen, and angiotensin II. In addition, we found that the exercise effects were modified by age, sex, and health status such that people aged <50 years, men, and people with type 2 diabetes, hypertension, dyslipidemia, or metabolic syndrome appeared to benefit more.
This meta-analysis showed that exercise significantly improved cardiorespiratory fitness and some cardiometabolic biomarkers. The effects of exercise were modified by age, sex, and health status. Findings from this study have significant implications for future design of targeted lifestyle interventions.
OBJECTIVE: Both in vitro and in vivo studies indicate that metformin inhibits cancer cell growth and reduces cancer risk. Recent epidemiological studies suggest that metformin therapy may reduce the ...risks of cancer and overall cancer mortality among patients with type 2 diabetes. However, data on its effect on colorectal cancer are limited and inconsistent. We therefore pooled data currently available to examine the association between metformin therapy and colorectal cancer among patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: The PubMed and SciVerse Scopus databases were searched to identify studies that examined the effect of metformin therapy on colorectal cancer among patients with type 2 diabetes. Summary effect estimates were derived using a random-effects meta-analysis model. RESULTS: The analysis included five studies comprising 108,161 patients with type 2 diabetes. Metformin treatment was associated with a significantly lower risk of colorectal neoplasm (relative risk RR 0.63 95% CI 0.50–0.79; P < 0.001). After exclusion of one study that investigated colorectal adenoma, the remaining four studies comprised 107,961 diabetic patients and 589 incident colorectal cancer cases during follow-up. Metformin treatment was associated with a significantly lower risk of colorectal cancer (0.63 0.47–0.84; P = 0.002). There was no evidence for the presence of significant heterogeneity between the five studies (Q = 4.86, P = 0.30; I2 = 18%). CONCLUSIONS: From observational studies, metformin therapy appears to be associated with a significantly lower risk of colorectal cancer in patients with type 2 diabetes. Further investigation is warranted.
Obesity, physical inactivity, and reduced physical fitness contribute to the rising burden of chronic diseases in China. We investigated these factors in Chinese adults over a 14-year period ...(2000-14) using data from randomised national surveys.
We did four national surveys in 2000, 2005, 2010, and 2014 among Chinese adults aged 20-59 years. We used BMI to assess underweight (<18·5 kg/m(2)), overweight (≥23·0 to <27·5 kg/m(2)), and obesity (≥27·5 kg/m(2)). Central obesity was defined as a waist circumference greater than 90 cm in men and greater than 85 cm in women. We assessed leisure-time physical activity (LTPA) by whether or not participants had completed the recommended minimum 150 min of moderate or 75 min of vigorous exercise per week. Indices for assessment of physical fitness were forced vital capacity, resting heart rate, hand grip strength, sit and reach distance, and time standing on one leg.
151 656 (78%) of 193 440 adults responded to the survey in 2000, 163 386 (84%) in 2005, 154 931 (80%) in 2010, and 146 703 (76%) in 2014. The prevalence of obesity increased from 8·6% in 2000, to 10·3% in 2005, 12·2% in 2010, and 12·9% in 2014 (estimated increase 0·32% per year, 95% CI 0·30-0·33; p<0·0001). The equivalent estimates were 37·4%, 39·2%, 40·7%, and 41·2% for overweight (estimated increase 0·27% per year, 95% CI 0·25-0·30; p<0·0001) and 13·9%, 18·3%, 22·1%, and 24·9% for central obesity (estimated increase 0·78% per year, 0·76-0·80; p<0·0001). The prevalence of overweight, obesity, and central obesity increased with age (all p<0·0001) and was higher in men than in women (all p<0·0001). We noted a simultaneous decrease in the prevalence of underweight (estimated decrease of 0·06% per year, 95% CI 0·04-0·07; p<0·0001). The proportion of adults meeting the minimum LTPA recommendation increased over time (17·2% in 2000, 18·1% in 2005, and 22·8% in 2014), with the estimated prevalence change per year being 0·33% (95% CI 0·24-0·42; p<0·0001) for underweight people, 0·50% (0·47-0·53; p<0·0001) for normal-weight people, 0·37% (0·34-0·40; p<0·0001) for overweight people, and 0·06% (0·00-0·13; p=0·044) for obese people. We noted deteriorations over time in all measures of physical fitness in normal-weight adults (all p<0·0001), apart from resting heart rate (p=0·69).
Despite increased participation in LTPA, we noted increases in overweight or obesity and a decrease in physical fitness in Chinese adults. Continued nationwide interventions are needed to promote physical activity and other healthy lifestyle behaviours in China.
National Physical Fitness Surveillance Center and Ministry of Science and Technology of the People's Republic of China.
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