ABSTRACT
INTRODUCTION: Numerous epidemiologic studies have investigated the link between nonalcoholic fatty liver disease (NAFLD) and long-term atrial fibrillation (AF) risk, but the results are surprisingly conflicting. AIM: Therefore, we systematically reviewed all published studies assessing the risk of AF in patients with NAFLD and conducted a meta-analysis. MATERIAL AND METHODS: We performed a literature search using PubMed, EMBASE and Cochrane Library databases in February 2017 with no restrictions. Two cohort studies and two cross-sectional studies were identified, involving a total of 5150 subjects (NAFLD: 1655; controls: 3495) in this meta-analysis. Data from selected studies were extracted and a meta-analysis was performed using a random effects model. RESULTS: Nonalcoholic fatty liver disease patients had a significantly higher risk of AF compared to controls (relative risk (RR): 2.61; 95% confidence interval (CI): 1.34-5.06, p = 0.00; I2 = 52.5%, p = 0.097). In a further analysis stratified by presence of type 2 diabetes, the increased risk was present predominantly in patients with type 2 diabetes (RR = 5.10; 95% CI: 2.43-10.7, p < 0.001; I2 = 0, p = 0.958). However, subjects without type 2 diabetes were at slightly increased risk of AF but the relative risk did not reach statistical significance (RR = 1.68; 95% CI: 0.99-2.82, p = 0.05; I2 = 0, p = 0.461). CONCLUSIONS: Our meta-analysis suggested that ultrasound-diagnosed NAFLD patients have a significantly higher risk for AF after adjustment for numerous important clinical risk factors for AF. These results need to be confirmed in large prospective studies.
ABSTRACT
Many epidemiologic literatures have investigated the link between PCOS and long-term stroke risk and all-cause mortality, but the results are surprisingly conflicting. A meta-analysis was performed to examine the link between polycystic ovary syndrome (PCOS) and the risk of stroke, death from any cause, and assessed whether BMI might explain a higher risk of stroke. We searched the PUBMED, EMBASE, and Cochrane Library databases with no restrictions. Nine Cohort studies were identified, involving a total of 237,647 subjects. Compared with those without PCOS, subjects with PCOS were significantly associated with a increased risk of developing stroke (OR = 1.36; 95% CI 1.09-1.70; p = .007). However, no significant association was observed between PCOS and all-cause death (OR = 1.21; 95% CI 0.88-1.66; p = .25). Moreover, after pooling the five studies with risk estimates adjusted for BMI, the association between PCOS and stroke was slightly attenuated, although the odds ratios did not reach statistical significance (OR = 1.24; 95% CI 0.98-1.59). In conclusion, PCOS is associated with significant increased risk for stroke, while there is no consistent evidence to indicate that PCOS influences all-cause death outcomes. Increased BMI is an important contributor to the relationship between PCOS and stroke risk. Further study is needed to clarify which subgroups of subjects with the PCOS are at higher risk for stroke and should focus on developing reliable device for risk stratification.
