| 1. |
- Bjørge, Tone, et al.
(författare)
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BMI and weight changes and risk of obesity-related cancers : a pooled European cohort study
- 2019
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Ingår i: International Journal of Epidemiology. - : Oxford University Press (OUP). - 1464-3685 .- 0300-5771. ; 48:6, s. 1872-1885
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Obesity is an established risk factor for several cancers. Adult weight gain has been associated with increased cancer risk, but studies on timing and duration of adult weight gain are relatively scarce. We examined the impact of BMI (body mass index) and weight changes over time, as well as the timing and duration of excess weight, on obesity- and non-obesity-related cancers. METHODS: We pooled health data from six European cohorts and included 221 274 individuals with two or more height and weight measurements during 1972-2014. Several BMI and weight measures were constructed. Cancer cases were identified through linkage with national cancer registries. Hazard ratios (HRs) of cancer with 95% confidence intervals (CIs) were derived from time-dependent Cox-regression models. RESULTS: During follow-up, 27 881 cancer cases were diagnosed; 9761 were obesity-related. The HR of all obesity-related cancers increased with increasing BMI at first and last measurement, maximum BMI and longer duration of overweight (men only) and obesity. Participants who were overweight before age 40 years had an HR of obesity-related cancers of 1.16 (95% CI 1.02, 1.32) and 1.15 (95% CI 1.04, 1.27) in men and women, respectively, compared with those who were not overweight. The risk increase was particularly high for endometrial (70%), male renal-cell (58%) and male colon cancer (29%). No positive associations were seen for cancers not regarded as obesity-related. CONCLUSIONS: Adult weight gain was associated with increased risk of several major cancers. The degree, timing and duration of overweight and obesity also seemed to be important. Preventing weight gain may reduce the cancer risk.
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| 2. |
- Fritz, Josef, et al.
(författare)
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The triglyceride-glucose index as a measure of insulin resistance and risk of obesity-related cancers
- 2020
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Ingår i: International Journal of Epidemiology. - : Oxford University Press (OUP). - 0300-5771 .- 1464-3685. ; 49:1, s. 193-204
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The role of insulin resistance as a mediator in the association of body mass index (BMI) with site-specific cancer risk has, to our knowledge, never been systematically quantified.METHODS: Altogether 510 471 individuals from six European cohorts, with a mean age of 43.1 years, were included. We used the triglyceride glucose product (TyG index) as a surrogate measure for insulin resistance. We fitted Cox models, adjusted for relevant confounders, to investigate associations of TyG index with 10 common obesity-related cancers, and quantified the proportion of the effect of BMI mediated through TyG index on the log-transformed hazard ratio (HR) scale.RESULTS: During a median follow-up of 17.2 years, 16 052 individuals developed obesity-related cancers. TyG index was associated with the risk of cancers of the kidney HR per one standard deviation increase 1.13, 95% confidence interval: 1.07 to 1.20], liver (1.13, 1.04 to 1.23), pancreas (1.12, 1.06 to 1.19), colon (1.07, 1.03 to 1.10) and rectum (1.09, 1.04 to 1.14). Substantial proportions of the effect of BMI were mediated by TyG index for cancers of the pancreas (42%), rectum (34%) and colon (20%); smaller proportions for kidney (15%) and liver (11%). Little or no mediation was observed for breast (postmenopausal), endometrial and ovarian cancer. Results were similar for males and females, except for pancreatic cancer where the proportions mediated were 20% and 91%, respectively.CONCLUSIONS: The TyG index was associated with increased risk of cancers of the digestive system and substantially mediated the effect of BMI, suggesting that insulin resistance plays a promoting role in the pathogenesis of gastrointestinal cancers.
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| 3. |
- Teleka, Stanley, et al.
(författare)
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Risk of bladder cancer by disease severity in relation to metabolic factors and smoking : A prospective pooled cohort study of 800,000 men and women
- 2018
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 143:12, s. 3071-3082
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies on metabolic factors and bladder cancer (BC) risk have shown inconsistent results and have commonly not investigated associations separately by sex, smoking, and tumor invasiveness. Among 811,633 participants in six European cohorts, we investigated sex-specific associations between body mass index (BMI), mid-blood pressure (BP, [systolic + diastolic]/2), plasma glucose, triglycerides, total cholesterol and risk of BC overall, non-muscle invasive BC (NMIBC) and muscle invasive BC (MIBC). Among men, we additionally assessed additive interactions between metabolic factors and smoking on BC risk. During follow-up, 2,983 men and 754 women were diagnosed with BC. Among men, triglycerides and BP were positively associated with BC risk overall (hazard ratio [HR] per standard deviation [SD]: 1.17 [95% confidence interval (CI) 1.06–1.27] and 1.09 [1.02–1.17], respectively), and among women, BMI was inversely associated with risk (HR: 0.90 [0.82–0.99]). The associations for BMI and BP differed between men and women (pinteraction ≤ 0.005). Among men, BMI, cholesterol and triglycerides were positively associated with risk for NMIBC (HRs: 1.09 [95% CI 1.01–1.18], 1.14 [1.02–1.25], and 1.30 [1.12–1.48] respectively), and BP was positively associated with MIBC (HR: 1.23 [1.02–1.49]). Among women, glucose was positively associated with MIBC (HR: 1.99 [1.04–3.81]). Apart from cholesterol, HRs for metabolic factors did not significantly differ between MIBC and NMIBC, and there were no interactions between smoking and metabolic factors on BC. Our study supports an involvement of metabolic aberrations in BC risk. Whilst some associations were significant only in certain sub-groups, there were generally no significant differences in associations by smoking or tumor invasiveness.
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