ABSTRACT
Purpose: Central obesity may contribute to breast cancer (BC); however, there is no dose-response relationship. This meta-analysis examined the effects of central obesity on BC and their potential dose-response relationship. Methods: In the present study, PubMed, Medline, Embase, and Web of Science were searched on 1 August 2022 for published articles. We included the prospective cohort and case-control studies that reported the relationship between central obesity and BC. Summary effect size estimates were expressed as risk ratios (RRs) or odds ratios (ORs) with 95% confidence intervals (95% CI) and were evaluated using random-effect models. The inconsistency index (I2) was used to quantify the heterogeneity magnitude derived from the random-effects Mantel-Haenszel model. Results: This meta-analysis included 57 studies (26 case-control and 31 prospective cohort) as of August 2022. Case-control studies indicated that waist circumference (WC) (adjusted OR = 1.18; 95% CI: 1.00-1.38; P = 0.051) and waist-to-hip ratio (WHR) (adjusted OR = 1.28; 95% CI: 1.07-1.53; P = 0.008) were significantly positively related to BC. Subgroup analysis showed that central obesity measured by WC increased the premenopausal (adjusted OR = 1.15; 95% CI: 0.99-1.34; P = 0.063) and postmenopausal (adjusted OR = 1.18; 95% CI: 1.03-1.36; P = 0.018) BC risk and the same relationship appeared in WHR between premenopausal (adjusted OR = 1.38; 95% CI: 1.19-1.59; P < 0.001) and postmenopausal (adjusted OR = 1.41; 95% CI: 1.22-1.64; P < 0.001). The same relationship was observed in hormone receptor-positive (HR+) (adjusted ORWC = 1.26; 95% CI: 1.02-1.57; P = 0.035, adjusted ORWHR = 1.41; 95% CI: 1.00-1.98; P = 0.051) and hormone receptor-negative (HR-) (adjusted ORWC = 1.44; 95% CI: 1.13-1.83; P = 0.003, adjusted ORWHR = 1.42; 95% CI: 0.95-2.13; P = 0.087) BCs. Prospective cohort studies indicated that high WC (adjusted RR = 1.12; 95% CI: 1.08-1.16; P < 0.001) and WHR (adjusted RR = 1.05; 95% CI: 1.018-1.09; P = 0.017) may increase BC risk. Subgroup analysis demonstrated a significant correlation during premenopausal (adjusted RR = 1.08; 95% CI: 1.02-1.14; P = 0.007) and postmenopausal (adjusted RR = 1.14; 95% CI: 1.10-1.19; P < 0.001) between BC and central obesity measured by WC, and WHR was significantly positively related to BC both premenopausal (adjusted RRpre = 1.04; 95% CI: 0.98-1.11; P = 0.169) and postmenopausal (adjusted RRpost = 1.04; 95% CI: 1.02-1.07; P = 0.002). Regarding molecular subtype, central obesity was significantly associated with HR+ (adjusted ORWC = 1.13; 95% CI: 1.07-1.19; P < 0.001, adjusted ORWHR = 1.03; 95% CI: 0.98-1.07; P = 0.244) and HR- BCs (adjusted ORWC =1.11; 95% CI: 0.99-1.24; P = 0.086, adjusted ORWHR =1.01; 95% CI: 0.91-1.13; P = 0.808). Our dose-response analysis revealed a J-shaped trend in the relationship between central obesity and BC (measured by WC and WHR) in case-control studies and an inverted J-shaped trend between BMI (during premenopausal) and BC in the prospective cohort. Conclusion: Central obesity is a risk factor for premenopausal and postmenopausal BC, and WC and WHR may predict it. Regarding the BC subtype, central obesity is proven to be a risk of ER+ and ER- BCs. The dose-response analysis revealed that when BMI (during premenopausal) exceeded 23.40 kg/m2, the risk of BC began to decrease, and WC higher than 83.80 cm or WHR exceeded 0.78 could efficiently increase the BC risk. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022365788.
ABSTRACT
Background: Physical activity (PA) is considered a favorable preventive intervention for postpartum depression (PPD), but evidence defining a corresponding dose-response relationship is lacking. This meta-analysis was conducted to assess the protective effects of PA on PPD and define a potential dose-response relationship between them. Methods: PubMed, Medline, Embase, and Web of Science were searched from 1968 to May 2022. Only randomized control trials (RCTs) and prospective studies were considered, and the PICOS tool was used to identify eligible articles based on the inclusion and exclusion criteria. Effect-size estimates were unified as odds ratio (OR) and 95% confidence interval (CI). We calculated the ORs and their 95% CI for studies that did not report them using the Practical Meta-Analysis Effect Size Calculator. Results: A total of 23 studies were eligible, including 14 RCTs and 9 prospective cohort studies. The overall analysis showed a statistically significant positive association between PA and PPD prevention (adjusted OR = 0.73; 95% CI: 0.61-0.87; P < 0.001). Subgroup analyses indicated that studies conducted in Europe demonstrated a significant correlation between PA and reduced PPD risk (adjusted OR = 0.85, 95% CI: 0.76-0.95, P = 0.004). Concerning PA type, sports activity was associated with relieving PPD symptoms (adjusted OR = 0.89, 95% CI: 0.78 to 1.00, P < 0.001), while work (adjusted OR = 1.05, 95% CI: 0.37-2.97, P = 0.065) and household activities (adjusted OR = 1.16, 95% CI: 0.89-1.52, P = 0.986) contributed to a greater risk of PPD. Our dose-response analysis revealed a reverse J-shaped trend between ascending PA duration and PPD incidence. Conclusion: This meta-analysis identified PA as a potential intervention to reduce the risk of PPD. The dose-response analysis revealed that at least 90 min of PA per week could efficiently decrease the risk of PPD. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022335731.
