The effects of N-acetylcysteine supplement on metabolic parameters in women with polycystic ovary syndrome: a systematic review and meta-analysis.

Objectives: Polycystic ovary syndrome (PCOS) is a common endocrine disease, often accompanied by metabolic disorders. Metformin, as an insulin sensitizer, is widely used to improve the metabolic function of PCOS, but may have gastrointestinal side effects. Emerging evidence suggests that N-acetylcysteine (NAC) improves metabolic parameters in PCOS and may be a potential alternative to metformin. Methods: We searched four online databases, PubMed, Embase, Web of Science, and Cochrane Library, from inception to April 1, 2023. The I2 statistic and Cochrane's Q test were employed to determine heterogeneity between studies, with an I2 value >50% or p < 0.1 considered significant. The data were expressed as standardized mean differences and corresponding 95% confidence intervals. Results: A total of 11 randomized controlled trials were included in the final analysis, including 869 women with PCOS. The results showed that NAC caused more changes in body mass index (SMD: -0.16, 95% CI: -0.40 to 0.08), body weight (SMD: -0.25, 95% CI: -0.50 to 0.00), fasting insulin (SMD: -0.24, 95% CI: -0.53 to 0.06), ratio of fasting blood glucose to fasting insulin (SMD: 0.38, 95% CI: -0.33 to 1.08), total cholesterol (SMD: -0.11, 95% CI: -0.39 to 0.17), triglycerides (SMD: -0.18, 95% CI: -0.63 to 0.28), and low-density lipoprotein (SMD: -0.09, 95% CI: -0.51 to 0.33) compared with metformin. Compared with metformin or placebo, NAC significantly reduced fasting blood-glucose levels (SMD: -0.23, 95% CI: -0.43 to -0.04; SMD: -0.54, 95% CI: -1.03 to -0.05, respectively). In addition, NAC significantly reduced total cholesterol (SMD: -0.74, 95% CI: -1.37 to -0.12), and this effect was observed when NAC was compared with placebo. However, NAC reduced HDL levels in women with PCOS compared with metformin (SMD: -0.14, 95% CI: -0.42 to 0.14). Conclusion: This study suggests that NAC is effective in improving metabolic parameters in PCOS and may be a promising nutritional supplement for the treatment of PCOS.Systematic review registration:https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=415172, identifier CRD42022339171.

Normal-weight central obesity: implications for diabetes mellitus.

Background: Current guidelines for obesity prevention and control focus on body mass index (BMI) and rarely address central obesity. Few studies have been conducted on the association between normal-weight central obesity and the risk of diabetes mellitus (DM). Methods: 26,825 participants from the National Health and Nutrition Examination Survey (NHANES) were included in our study. A weighted multivariate logistic regression model was used to analyze the relationship between different obesity patterns and the risk of DM. Results: Our results suggest that normal-weight central obesity is associated with an increased risk of DM (OR: 2.37, 95% CI: 1.75-3.23) compared with normal-weight participants without central obesity. When stratified by sex, men with normal-weight central obesity, obesity and central obesity were found to have a similar risk of DM (OR: 3.83, 95% CI: 2.10-5.97; OR: 4.20, 95% CI: 3.48-5.08, respectively) and a higher risk than all other types of obesity, including men who were overweight with no central obesity (OR: 1.21, 95% CI: 0.96-1.51) and obese with no central obesity (OR: 0.53, 95% CI: 0.30-0.91). Conclusion: Our results highlight the need for more attention in people with central obesity, even if they have a normal BMI.

The association of central and extremity circumference with all-cause mortality and cardiovascular mortality: a cohort study.

Background: Central obesity increases the risk of several diseases, including diabetes, cardiovascular disease (CVD), and cancer. However, the association between extremity obesity and mortality has not been extensively evaluated. The objective of this study was to investigate the quantitative effects of waist circumference (WC), arm circumference (AC), calf circumference (CC), and thigh circumference (TC) on all-cause mortality and CVD mortality. Methods: The study used data from the National Health and Nutrition Examination Survey (NHANES) sample survey from 1999 to 2006. A total of 19,735 participants were included in the study. We divided the participants into four groups (Q1-Q4) and used Q1 as a reference to compare the risk of all-cause mortality and CVD mortality in Q2-Q4. COX proportional hazard regression model was used to analyze the relationship between WC, AC, CC and TC on all-cause and CVD mortality. In addition, we conducted a stratified analysis of gender. Results: After a mean follow-up of 11.8 years, we observed a total of 3,446 deaths, of which 591 were due to cardiovascular disease. The results showed that for both men and women, compared to the first group, the risk of all-cause mortality was significantly higher in the other three groups of WC and significantly lower in the other three groups of AC, CC, and TC. Similar results were observed after adjusting for confounding factors such as demographics. Conclusions: Our results show that all-cause and CVD mortality are positively associated with measures of central obesity and negatively associated with measures of extremity obesity, and that AC, CC, and TC can be used as potential tools to measure prognosis in the general population.

Early menopause is associated with increased risk of heart failure and atrial fibrillation: A systematic review and meta-analysis.

OBJECT: Menopause is linked to a higher risk of cardiovascular disease. However, it is unclear whether premature menopause (defined as menopause before the age of 40 years) or early menopause (defined as menopause before the age of 45 years) is associated with an increased risk of heart failure or atrial fibrillation. This study aimed to examine the most reliable evidence on the relationship between early menopause and the risk of heart failure and atrial fibrillation. METHODS: A comprehensive literature search was performed in three online databases, Embase, Web of Science, and PubMed, from database establishment to April 1, 2023. The results were presented as hazard ratios with 95 % confidence intervals. The I2 statistic was employed to assess heterogeneity, and the Egger's test was used to determine publication bias. RESULTS: Nine cohort studies were included in the analysis, with a total of 6,255,783 postmenopausal women. Women with premature and early menopause had an increased risk of heart failure (HR: 1.39, 95 % CI: 1.31-1.47; HR: 1.23, 95 % CI: 1.10-1.37, respectively) and atrial fibrillation (HR: 1.15, 95 % CI: 1.01-1.31; HR: 1.08, 95 % CI: 1.04-1.13, respectively) when compared with women who had undergone menopause after the age of 45 years. Subgroup analysis showed that, compared with early menopause, premature menopause has a stronger association with an increased risk of heart failure and atrial fibrillation. CONCLUSIONS: Women who undergo premature menopause or early menopause have a higher risk of heart failure and atrial fibrillation compared with women who undergo menopause in the normal age range. These reproductive factors need to be considered for measures that might reduce the risk of heart failure and atrial fibrillation.

The risk of long-term cardiometabolic disease in women with premature or early menopause: A systematic review and meta-analysis.

Background: Transition into menopause is associated with an increased risk of cardiovascular disease (CVD). However, it is unclear whether the association exists between premature menopause (defined as age at menopause 40 years) or early menopause (defined as age at menopause 40-45 years) and CVD or cardiovascular risk factors. The aim of this review was to comprehensively evaluate and meta-analyze the most reliable evidence about the relationship between menopausal age and the risk of long-term cardiometabolic disease. Methods: A comprehensive literature search of the PubMed, Web of Science, and Embase databases from inception to October 1, 2022, for titles and abstracts with a restriction to English language papers led to the discovery of the studies. Data are expressed as the Hazard Ratio (HR) with 95% confidence intervals (CI). The degree of heterogeneity was measured using the I-square (I 2) index. Results: 921,517 participants from 20 cohort studies published between 1998 and 2022 were considered. Compared to women with menopause at age >45 years, women with premature menopause (PM) or early menopause (EM) had a higher risks of type 2 diabetes (RR: 1.32, 95% CI: 1.08-1.62; RR: 1.11, 95% CI: 0.91-1.36, respectively), hyperlipidemia (RR: 1.21, 95% CI: 1.05-1.39; RR: 1.17, 95% CI: 1.02-1.33, respectively), coronary heart disease (RR: 1.52, 95% CI: 1.22-1.91; RR: 1.19, 95% CI: 1.07-1.32, respectively), stroke (RR: 1.27, 95% CI: 1.02-1.58; RR: 1.13, 95% CI: 0.97-1.32, respectively) and total cardiovascular event (RR: 1.36, 95% CI: 1.16-1.60; RR: 1.14, 95% CI: 0.97-1.35, respectively). No difference was found for hypertension in PM or EM women (RR: 0.98, 95% CI: 0.89-1.07; RR: 0.97, 95% CI: 0.91-1.04, respectively). Additionally, we also found that PM women, but not EM women, were linked with an increased risk of ischemic and hemorrhagic stroke. However, this is not in line with the conclusion that both PM and EM had a higher risk of total stroke. Conclusion: Women with PM or EM have a higher risk of developing long-term CVD, compared to women with menopause at age >45 years. Therefore, we recommend early lifestyle interventions (e.g., maintaining a healthy lifestyle) and medical treatments (e.g., timely initiation of menopausal hormone therapy) to decrease the risk of cardiometabolic disease in early or premature menopausal women. Systematic Review Registration: PROSPERO, identifier CRD42022378750.