Background: This meta-analysis was performed to investigate the effect of serum lipids on the risk of breast cancer incidence. Methods: PubMed, Web of Science, Scopus, and EMBASE were searched systematically from January 1998 to April 2019. Inclusion criteria were English observational studies (cohort or case-control) and the concentration of at least one of the lipid profile components (total cholesterol/triglycerides/low-density lipoprotein cholesterol/high-density lipoprotein cholesterol) measured before a diagnosis of breast cancer (BC). The studies were included in which the relative risk (RR) had been reported with 95% confidence intervals (CIs). A random-effects model was used. Results: A total of 25 studies were found, including 2,882,789 participants in cohort studies with 45,481 cases with BC, and 1983 BC cases and 2963 case-control studies. Combined RR of cohort studies for the highest versus lowest for the BC was LDL-C: 0.95 (95% CI: 0.89–1.01), triglycerides (TG): 0.95 (95% CI: 0.91–0.99; P = 0.02), total cholesterol (TC): 0.98 (95% CI: 0.91–1.05), and HDL-C: 0.86 (95% CI: 0.63–1.18). Combined RR of case-control studies for the highest versus lowest was LDL-C: 1.08 (95% CI: 0.78–1.48), TG: 1.73 (95% CI: 0.94–3.18), TC: 1.02 (95% CI: 0.80–1.29), and HDL-C: 0.79 (95% CI: 0.65–0.97). Conclusions: Based on the results, it can be concluded that only TG but not TC and/or LDL-C had a significant inverse association with the risk of BC incidence. HDL-C showed a significant protective effect against breast cancer in postmenopausal women and case-control studies.

Background: One billion worldwide population is living in slum areas that mostly accompanied with high rates of poverty, illiteracy, unemployment, unhealthy situation, and inappropriate health-care services. The prediction of enormous growth of slums by 2030 led to a raise to address the “plight of slums” in Sustainable Development Goals (SDGs). Methods: To address evidence-based health-related priorities, we conducted a systematic review to summarizing evidences on health situations of slums population in Iran. Six electronic databases were systematically searched for published studies without any restriction on age, sex, and language to assess health situations of slums in Iran reported by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. All identified articles were screened, quality assessed, and data extracted by two authors independently. Results: The finding of this systematic review in addition to overall view categorized in five categories: health system, reproductive health, infectious diseases, noncommunicable diseases and their risk factors, social issues besides overall situation of Slums. Conclusions: Community-based participatory interventions with socioeconomic approach on modifiable risk factors; active response of health system; establishment new health care centers in slum areas; augmenting the quality of care; active case finding; and elevating health knowledge, attitude, and practice is crucial to achieve SDG's in Slum area.