OBJECTIVE: This study investigated the relationship between adiposity, lifetime physical activities and serum adiponectin as breast cancer risk factors among Malaysian women in Klang Valley, Malaysia.
DESIGN: A case-control study was carried out among 70 newly diagnosed breast cancer patients and 138 controls aged 29 to 65 years old in Klang Valley.
SUBJECTS: The inclusion criteria for both groups were not having menstruation for premenopausal women, no evidence of pregnancy, not lactating and no chronic diseases such as hypertension and diabetes at the time of data collection. In addition, the cases must be pathologically newly diagnosed with breast cancer (stage I to III) and not on any therapy for cancer, with the exception of surgery. The controls were matched with cases for age +/- 5 years and menopausal status.
MEASUREMENTS: Subjects were interviewed to obtain information on socio-demography, health and reproductive history using a pretested questionnaire. Subjects were also asked on their engagement of physical activity since secondary school. Anthropometric parameters included height, weight, waist and hips were also measured. A total of 6 ml of fasting venous blood was drawn for analysis of serum adiponectin in duplicate using Linko Adiponectin ELISA Kit. Fasting blood glucose (FBG) and blood pressure were also measured.
RESULTS: Mean body mass index (BMI) among cases and controls were not significantly different (p> 0.05) at 26.1 -/+ 4.8 kg/m2 and 25.3 -/+ 4.5 kg/m2, respectively. FBG among cases (6.3 -/+ 1.8 mmol/L) was higher than controls (5.6 -/+ 1.1 mmol/L) (p<0.05). Waist hip ratio (WHR) of cases (0.85 -/+ 0.07) was also higher than controls (0.80 -/+ 0.06) (p<0.05). Abdominal obesity (WHR > 0.85) increased risk of breast cancer by three folds [Adjusted OR 3.3 (95%CI 1.8-6.2)] (p<0.05). Adiponectin level was inversely related to waist circumference (r=-0.510, p=0.000), BMI (r=-0.448, p=0.000) and FBG (r=-0.290, p=0.026). Adiponectin level in cases (11.9 -/+ 4.8 microg/ml) were lower than controls (15.2 -/+ 7.3 microg/ml) (p<0.05). A greater reduction of breast cancer risk was observed with the increasing level of serum adiponectin level according to percentiles (p<0.05). Subjects with mean serum adiponectin level at the highest quintile (> 75th)( >or= 16.7 microg/ml) had 80% reduced risk of breast cancer [Adjusted OR 0.2 (0.0-0.6)](p<0.05). A higher percentage of cases (47%) had not engaged in any physical activity throughout life as compared to controls (19%)[Adjusted OR 3.7 (1.7-7.7)](p<0.001).
CONCLUSIONS: Abdominal obesity and physical inactivity throughout life were associated with low serum adiponectin and breast cancer risk among subjects. Thus, it is essential for Malaysian women to be physically active and achieve a healthy waistline in order to increase serum adiponectin level and reduce breast cancer risk.
METHODS: This is a meta-analysis of seven prospective cohort studies participating in the CHANCES consortium including 18 668 men and 24 751 women with a mean age of 62 and 63 years, respectively. Harmonised individual participant data from all seven cohorts were analysed separately and alternatively for each anthropometric indicator using multivariable Cox proportional hazards models.
RESULTS: After a median follow-up period of 12 years, 1656 first-incident obesity-related cancers (defined as postmenopausal female breast, colorectum, lower oesophagus, cardia stomach, liver, gallbladder, pancreas, endometrium, ovary, and kidney) had occurred in men and women. In the meta-analysis of all studies, associations between indicators of adiposity, per s.d. increment, and risk for all obesity-related cancers combined yielded the following summary hazard ratios: 1.11 (95% CI 1.02-1.21) for BMI, 1.13 (95% CI 1.04-1.23) for WC, 1.09 (95% CI 0.98-1.21) for HC, and 1.15 (95% CI 1.00-1.32) for WHR. Increases in risk for colorectal cancer were 16%, 21%, 15%, and 20%, respectively per s.d. of BMI, WC, HC, and WHR. Effect modification by hormone therapy (HT) use was observed for postmenopausal breast cancer (Pinteraction<0.001), where never HT users showed an ∼20% increased risk per s.d. of BMI, WC, and HC compared to ever users.
CONCLUSIONS: BMI, WC, HC, and WHR show comparable positive associations with obesity-related cancers combined and with colorectal cancer in older adults. For postmenopausal breast cancer we report evidence for effect modification by HT use.
METHODS: We investigated overall obesity and abdominal adiposity in relation to SIC in the European Prospective Investigation into Cancer and Nutrition (EPIC), a large prospective cohort of approximately half a million men and women from ten European countries. Overall obesity and abdominal obesity were assessed by body mass index (BMI), waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR). Multivariate Cox proportional hazards regression modeling was performed to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs). Stratified analyses were conducted by sex, BMI, and smoking status.
RESULTS: During an average of 13.9 years of follow-up, 131 incident cases of SIC (including 41 adenocarcinomas, 44 malignant carcinoid tumors, 15 sarcomas and 10 lymphomas, and 21 unknown histology) were identified. WC was positively associated with SIC in a crude model that also included BMI (HR per 5-cm increase = 1.20, 95 % CI 1.04, 1.39), but this association attenuated in the multivariable model (HR 1.18, 95 % CI 0.98, 1.42). However, the association between WC and SIC was strengthened when the analysis was restricted to adenocarcinoma of the small intestine (multivariable HR adjusted for BMI = 1.56, 95 % CI 1.11, 2.17). There were no other significant associations.
CONCLUSION: WC, rather than BMI, may be positively associated with adenocarcinomas but not carcinoid tumors of the small intestine.
IMPACT: Abdominal obesity is a potential risk factor for adenocarcinoma in the small intestine.
METHODS AND RESULTS: A total of 159 755 adults aged ≥35 years from Mexico City were enrolled in a prospective study and followed for 16 years. Cox regression, adjusted for confounders, yielded mortality rate ratios (RRs) associated with three markers of abdominal adiposity (waist circumference, waist-hip ratio, and waist-height ratio) and one marker of gluteo-femoral adiposity (hip circumference) for cause-specific mortality before age 75 years. To reduce reverse causality, deaths in the first 5 years of follow-up and participants with diabetes or other prior chronic disease were excluded. Among 113 163 participants without prior disease and aged 35-74 years at recruitment, all adiposity markers were positively associated with vascular-metabolic mortality. Comparing the top versus bottom tenth of the sex-specific distributions, the vascular-metabolic mortality RRs at ages 40-74 years were 2.32 [95% confidence interval (CI) 1.84-2.94] for waist circumference, 2.22 (1.71-2.88) for the waist-hip ratio, 2.63 (2.06-3.36) for the waist-height ratio, and 1.58 (1.29-1.93) for hip circumference. The RRs corresponding to each standard deviation (SD) higher usual levels of these adiposity markers were 1.34 (95% CI 1.27-1.41), 1.31 (1.23-1.39), 1.38 (1.31-1.45), and 1.18 (1.13-1.24), respectively. For the markers of abdominal adiposity, the RRs did not change much after further adjustment for other adiposity markers, but for hip circumference the association was reversed; given body mass index and waist circumference, the RR for vascular-metabolic mortality for each one SD higher usual hip circumference was 0.80 (0.75-0.86).
CONCLUSIONS: In this study of Mexican adults, abdominal adiposity (and in particular the waist-height ratio) was strongly and positively associated with vascular-metabolic mortality. For a given amount of general and abdominal adiposity, however, higher hip circumference was associated with lower vascular-metabolic mortality.