Metabolically defined body size and body shape phenotypes and risk of postmenopausal breast cancer in the European Prospective Investigation into Cancer and Nutrition.

BACKGROUND: Excess body fatness and hyperinsulinemia are both associated with an increased risk of postmenopausal breast cancer. However, whether women with high body fatness but normal insulin levels or those with normal body fatness and high levels of insulin are at elevated risk of breast cancer is not known. We investigated the associations of metabolically defined body size and shape phenotypes with the risk of postmenopausal breast cancer in a nested case-control study within the European Prospective Investigation into Cancer and Nutrition. METHODS: Concentrations of C-peptide-a marker for insulin secretion-were measured at inclusion prior to cancer diagnosis in serum from 610 incident postmenopausal breast cancer cases and 1130 matched controls. C-peptide concentrations among the control participants were used to define metabolically healthy (MH; in first tertile) and metabolically unhealthy (MU; >1st tertile) status. We created four metabolic health/body size phenotype categories by combining the metabolic health definitions with normal weight (NW; BMI < 25 kg/m2 , or WC < 80 cm, or WHR < 0.8) and overweight or obese (OW/OB; BMI ≥ 25 kg/m2 , or WC ≥ 80 cm, or WHR ≥ 0.8) status for each of the three anthropometric measures separately: (1) MHNW, (2) MHOW/OB, (3) MUNW, and (4) MUOW/OB. Conditional logistic regression was used to compute odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Women classified as MUOW/OB were at higher risk of postmenopausal breast cancer compared to MHNW women considering BMI (OR = 1.58, 95% CI = 1.14-2.19) and WC (OR = 1.51, 95% CI = 1.09-2.08) cut points and there was also a suggestive increased risk for the WHR (OR = 1.29, 95% CI = 0.94-1.77) definition. Conversely, women with the MHOW/OB and MUNW were not at statistically significant elevated risk of postmenopausal breast cancer risk compared to MHNW women. CONCLUSION: These findings suggest that being overweight or obese and metabolically unhealthy raises risk of postmenopausal breast cancer while overweight or obese women with normal insulin levels are not at higher risk. Additional research should consider the combined utility of anthropometric measures with metabolic parameters in predicting breast cancer risk.

Body mass index, abdominal fatness, weight gain and the risk of urinary incontinence: a systematic review and dose-response meta-analysis of prospective studies.

BACKGROUND: Adiposity has been associated with elevated risk of urinary incontinence in epidemiological studies; however, the strength of the association has differed between studies. OBJECTIVES: To conduct a systematic literature review and dose-response meta-analysis of prospective studies on adiposity and risk of urinary incontinence. SEARCH STRATEGY: We searched PubMed and Embase databases up to 19 July 2017. SELECTION CRITERIA: Prospective cohort studies were included. DATA COLLECTION AND ANALYSIS: Data were extracted by one reviewer and checked for accuracy by a second reviewer. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random effects models. MAIN RESULTS: Twenty-four prospective studies were included. The summary RR per 5 kg/m2 increment in body mass index (BMI) was 1.20 (95% CI 1.16-1.25, I2  = 62%, n = 11) for population-based studies and 1.19 (95% CI 1.08-1.30, I2  = 87.1%, n = 8) for pregnancy-based studies, 1.18 (95% CI 1.14-1.22, I2  = 0%, n = 2) per 10 cm increase in waist circumference and 1.34 (95% CI 1.11-1.62, I2  = 90%, n = 2) per 10 kg of weight gain. Although the test for nonlinearity was significant for BMI, P = 0.04, the association was approximately linear. For subtypes of urinary incontinence the summary RR per 5 BMI units was 1.45 (95% CI 1.25-1.68, I2  = 85%, n = 3) for frequent incontinence, 1.52 (95% CI 1.37-1.68, I2  = 34%, n = 4) for severe incontinence, 1.33 (95% CI 1.26-1.41, I2  = 0%, n = 8) for stress incontinence, 1.26 (95% CI 1.14-1.40, I2  = 70%, n = 7) for urge incontinence, and 1.52 (95% CI 1.36-1.69, I2  = 0%, n = 3) for mixed incontinence. CONCLUSION: These results suggest excess weight may increase risk of urinary incontinence. TWEETABLE ABSTRACT: Overweight and obesity increase the risk of urinary incontinence.

Postmenopausal hormone use and cutaneous melanoma risk: A French prospective cohort study.

Cutaneous melanoma has been suspected to be influenced by female hormones. Several studies reported a positive association between menopausal hormone therapy (MHT) use and melanoma risk; however, previous findings were conflicting. We sought to explore the associations between MHT use and melanoma risk in a prospective cohort of women in France, where a particularly wide variety of MHT formulations are available. E3N is a prospective cohort of 98,995 French women aged 40-65 years in 1990. MHT use was assessed through biennial self-administered questionnaires. We used Cox proportional hazards regression models adjusted for age and skin cancer risk factors. Over 1990-2008, 444 melanoma cases were ascertained among 75,523 postmenopausal women. Ever use of MHT was associated with a higher melanoma risk (hazard ratio (HR) = 1.35, 95% confidence intervals (CI) = 1.07-1.71). The association was strongest among past users (HR = 1.55, CI = 1.17-2.07, homogeneity for past vs. recent use: p = 0.11), and users of MHT containing norpregnane derivatives (HR = 1.59, CI = 1.11-2.27), although with no heterogeneity across types of MHT (p = 0.13). Among MHT users, the association was similar across durations of use. However, a higher risk was observed when treatment onset occurred shortly after menopause (<6 months: HR = 1.55, CI = 1.16-2.07 vs. ≥2 years). Associations between MHT use and melanoma risk were similar after adjustment for UV exposure, although MHT users were more likely to report sunscreen use than nonusers. Our data do not support a strong association between MHT use and melanoma risk. Further investigation is needed to explore potential effect modification by UV exposure on this relationship.

Oral contraceptive use and cutaneous melanoma risk: a French prospective cohort study.

Cutaneous melanoma has been suspected to be influenced by female hormones. Several studies reported a positive association between oral contraceptive (OC) use and melanoma risk. However, findings were conflicting and data from large prospective studies are lacking. E3N is a prospective cohort of 98,995 French women aged 40-65 years at inclusion in 1990. Exposure to lifetime OC use was assessed in 1992 and through biennial questionnaire updates. To assess the association between OC use and melanoma risk, we used Cox models adjusted for age, pigmentary traits, residential ultraviolet (UV) exposure in county of birth and at inclusion and family history of skin cancer. Over 1992-2008, 539 melanoma cases were ascertained among 79,365 women. In age-adjusted models, we found a modest positive association between ever use of OCs and melanoma risk (hazard ratio (HR) = 1.18, 95% confidence intervals (CIs) = 0.98-1.42), which was reduced after adjustment (HR = 1.14, 95% CI = 0.95-1.38). The association was stronger in long-term users (duration ≥10 years: HR = 1.33, 95% CI = 1.00-1.75) and in women who used high-estrogen OCs (HR = 1.27, 95% CI = 1.04-1.56). Among users, there was an inverse association with age at first use (ptrend < 0.01), but no evidence of an association with age at last use or time since last use. OC use was positively associated with tanning bed use (OR = 1.14, CI = 1.01-1.29), sunburns (ptrend = 0.5) and sunscreen use (OR = 1.13, CI = 1.00-1.28) since age 25. Overall, our findings do not support a strong association between OC use and melanoma risk and suggest intentional UV exposure in OC users, which supports a potential confusion by UV exposure in this relationship.