Having cancer may increase the risk of developing diabetes
Researchers examined an extensive data set consisting of 112 million blood samples from 1.3 million Danes, of whom more than 50,000 developed cancer. They included 51,353 incident cancer case subjects diagnosed from 2004 to 2015 living in the Greater Copenhagen area without type 2 diabetes, defined according to one measurement of plasma or serum glucose 11 mmol/L or HbA1c 6.5% (48 mmol/mol), at diagnosis, each with 10 cancer- and type 2 diabetes–free age- and sex-matched control subjects. In Denmark, health care is public and free for all residents. They sampled all 112 million tests from 1.3 million individuals, performed by the Copenhagen General Practitioners’ Laboratory, contained in the Copenhagen Primary Care Laboratory Database (CopLab) (2015-57-0121) from 2000 to 2015, data for which were merged with data on incident cancer from the Danish Cancer Registry. Only cancer types with >1,000 incident cases with individuals aged >30 years were included. Individuals with diabetes prior to the cancer diagnosis were excluded. The median follow-up time was 2.34 years (interquartile range 0.70–5.53) for all case subjects and 4.41 years (2.04–7.40) for cancer-free control subjects.

They found an increased hazard of new-onset type 2 diabetes for all cancers (hazard ratio [HR] 1.09; 95% CI 1.03–1.14). The hazard of new-onset type 2 diabetes for different cancer types in comparisons with control subjects was particularly strong for pancreatic cancer (HR 5.00; 95% CI 3.62–6.90), cancer of the brain and other parts of the nervous system (HR 1.54; 95% CI 1.22–1.95), and cancer of the corpus uteri (HR 1.41; 95% CI 1.10–1.84).

Overall, the study finds an excess mortality of 21% in patients who develop diabetes after being diagnosed with cancer. The study also concludes that cancer patients who develop diabetes die sooner than survivors without diabetes.

Source: https://diabetesjournals.org/care/article/45/6/e105/146857/Incidence-of-New-Onset-Type-2-Diabetes-After