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Background: Results regarding telomere length and cancer risk are conflicting. We tested the hypothesis that long telomeres are associated with increased risk of any cancer and specific cancer types in genetic and observational analyses.Methods: Individuals (N = 95 568) from the Copenhagen City Heart Study and the Copenhagen General Population Study had the telomere length-associated genotypes rs7726159 (TERT), rs1317082 (TERC), and rs2487999 (OBFC1) determined, and 65 176 had telomere length measured. A total of 10 895 individuals had had a cancer diagnosis. Endpoints were any cancer and 25 specific cancer types. We conducted Cox regression analyses and logistic regression analyses. The three genotypes were combined as an allele sum.Results: Telomere length increased 67 base-pairs [95% confidence interval (CI) 61-74] per allele. In logistic regression models, the per-allele odds ratio (OR) for cancer was 1.05 (95% CI 1.03-1.07) for the allele sum, 1.05 (1.02-1.09) for rs7726159, 1.05 (1.02-1.08) for rs1317082 and 1.07 (1.02-1.12) for rs2487999. In contrast, the hazard ratio for any cancer was 1.01 (1.00-1.01) per 200-base-pair increase in telomere length in multivariable adjusted observational analysis. In genetic analyses according to specific cancer types, the per-allele odds ratio was 1.19 (1.12-1.27) for melanoma and 1.14 (1.06-1.22) for lung cancer.Conclusions: Genetic determinants of long telomeres are associated with increased cancer risk, particularly melanoma and lung cancer. This genetic predisposition to enhanced telomere maintenance may represent a survival advantage for pre-cancerous cells, allowing for multiple cell divisions leading to cancer development. [ABSTRACT FROM AUTHOR]

Background: In the clinic, the combination of obesity and chronic obstructive pulmonary disease (COPD) has been increasing. However, whether high body mass index (BMI) affects the risk of exacerbations and pneumonias in individuals with COPD is presently unknown. Genetics can be used to assess the causal role of high BMI in exacerbations and pneumonias in individuals with COPD. We tested the hypothesis that high BMI is associated with an increased risk of exacerbations and pneumonias in individuals with COPD, both observationally and genetically.Methods: We genotyped 93 894 individuals of Danish descent, aged 20-100 years, from the Copenhagen General Population Study, for FTO (rs9939609), MC4R (rs17782313) and TMEM18 (rs6548238), and created an allele score. A total of 10 883 individuals had spirometric COPD with forced expiratory volume in 1 s (FEV1) / forced vital capacity (FVC) < lower limit of normal (LLN). In these individuals, we observed 1453 exacerbations and 3390 pneumonias during 4.7 years of follow-up.Results: For each increase in allele score, BMI was 0.28 kg/m2 [95% confidence interval (CI): 0.25-0.30) higher. Age- and sex-adjusted genetic hazard ratios (HRs) per one allele score increase in individuals with COPD were 1.13 (1.01-1.27) for exacerbations, 1.10 (1.03-1.19) for pneumonias and 1.12 (1.04-1.21) for exacerbations and/or pneumonias. Corresponding multivariable adjusted observational HRs per unit (kg/m2) BMI increase were 0.98 (0.95-1.01), 0.99 (0.96-1.03) and 0.99 (0.96-1.01), respectively.Conclusions: Genetically determined high BMI was associated with an increased risk of recurrent exacerbations and pneumonias in individuals with COPD, whereas this was not the case for observationally determined high BMI. The genetic data are compatible with the notion that high BMI leads to increased risk of exacerbations and pneumonias in individuals with COPD. [ABSTRACT FROM AUTHOR]