Abstract
Aims: We evaluated the relationship between body mass index (BMI) and cancer mortality in incident type 2 diabetes.
Methods: We used the Clinical Practice Research Datalink GOLD (1998-2015), linked with the Office of National Statistics mortalities, and derived an incident type 2 diabetes cohort (N: 176,886; aged 30-85 years). We determined BMI ±12 months diabetes diagnosis. The primary outcome was cancer mortality, categorised into deaths from obesity-related cancers (ORCs) and non-ORCs. Secondary outcomes were site-specific cancer mortality and main causes of deaths (cancer, cardiovascular disease [CVD], non-cancer non-CVD). We developed gender-specific Cox models and expressed risk as hazard ratios (HR) and 95% confidence intervals (CIs), stratified by smoking status.
Results: With 886,850 person years follow-up, 7,593 cancer deaths occurred. Among women who never smoked, there were positive associations between BMI and deaths from endometrial (HR per 5 kg/m2: 1.43 [95% CI 1.26-1.61]. Among men, associations between BMI and ORC mortality were inverse but attenuated towards null among never smokers and excluding deaths in the first 2 years. In men, the proportion of CVD deaths increased from 36.8% in BMI category 22.5 to 24.9 kg/m2 to 43.6% in BMI category ≥ 40 kg/m2 (p < 0.001).
Conclusions: We found some relationships between BMI and cancer mortality in patients with type 2 diabetes, but interpretations need to account for smoking status, reverse causality, and deaths from CVD.
Methods: We used the Clinical Practice Research Datalink GOLD (1998-2015), linked with the Office of National Statistics mortalities, and derived an incident type 2 diabetes cohort (N: 176,886; aged 30-85 years). We determined BMI ±12 months diabetes diagnosis. The primary outcome was cancer mortality, categorised into deaths from obesity-related cancers (ORCs) and non-ORCs. Secondary outcomes were site-specific cancer mortality and main causes of deaths (cancer, cardiovascular disease [CVD], non-cancer non-CVD). We developed gender-specific Cox models and expressed risk as hazard ratios (HR) and 95% confidence intervals (CIs), stratified by smoking status.
Results: With 886,850 person years follow-up, 7,593 cancer deaths occurred. Among women who never smoked, there were positive associations between BMI and deaths from endometrial (HR per 5 kg/m2: 1.43 [95% CI 1.26-1.61]. Among men, associations between BMI and ORC mortality were inverse but attenuated towards null among never smokers and excluding deaths in the first 2 years. In men, the proportion of CVD deaths increased from 36.8% in BMI category 22.5 to 24.9 kg/m2 to 43.6% in BMI category ≥ 40 kg/m2 (p < 0.001).
Conclusions: We found some relationships between BMI and cancer mortality in patients with type 2 diabetes, but interpretations need to account for smoking status, reverse causality, and deaths from CVD.
| Original language | English |
|---|---|
| Journal | Diabetes, Obesity and Metabolism |
| Early online date | 6 Dec 2021 |
| DOIs | |
| Publication status | Published - 6 Dec 2021 |
Research Beacons, Institutes and Platforms
- Manchester Cancer Research Centre
