title: Type 2 diabetes mellitus, glycemic control, and cancer risk.
abstract: Type 2 diabetes mellitus is characterized by prolonged hyperinsulinemia, insulin resistance, and progressive hyperglycemia. Disease management relies on glycemic control through diet, exercise, and pharmacological intervention. The goal of the present study was to examine the effects of glycemic control and the use of glucose-lowering medication on the risk of breast, prostate, and colon cancer. Patients diagnosed with type 2 diabetes mellitus (N=9486) between 1 January 1995 and 31 December 2009 were identified and data on glycemic control (hemoglobin A1c, glucose), glucose-lowering medication use (insulin, metformin, sulfonylurea), age, BMI, date of diabetes diagnosis, insurance status, comorbidities, smoking history, location of residence, and cancer diagnoses were electronically abstracted. Cox proportional hazards regression modeling was used to examine the relationship between glycemic control, including medication use, and cancer risk. The results varied by cancer type and medication exposure. There was no association between glycemic control and breast or colon cancer; however, prostate cancer risk was significantly higher with better glycemic control (hemoglobin A1c ≤ 7.0%). Insulin use was associated with increased colon cancer incidence in women, but not with colon cancer in men or breast or prostate cancer risk. Metformin exposure was associated with reduced breast and prostate cancer incidence, but had no association with colon cancer risk. Sulfonylurea exposure was not associated with risk of any type of cancer. The data reported here support hyperinsulinemia, rather than hyperglycemia, as a major diabetes-related factor associated with increased risk of breast and colon cancer. In contrast, hyperglycemia appears to be protective in the case of prostate cancer.
authors: aDepartment of Hematology/Oncology, Marshfield Clinic Weston Center, Weston bMarshfield Clinic Research Foundation, Marshfield cMarshfield Clinic Cancer Care at St Michaels, Stevens Point, Wisconsin, USA dSchool of Population Health, University of Queensland, Brisbane, Queensland, Australia.
authors: Adedayo A
authors: AA
authors: Onitilo
authors: Rachel V
authors: RV
authors: Stankowski
authors: Richard L
authors: RL
authors: Berg
authors: Jessica M
authors: JM
authors: Engel
authors: Ingrid
authors: I
authors: Glurich
authors: Gail M
authors: GM
authors: Williams
authors: Suhail A
authors: SA
authors: Doi
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications* / Q000628:therapy*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007328:Insulin / Q000627:therapeutic use; D008297:Male; D008687:Metformin / Q000627:therapeutic use; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; D008687:Metformin; C517652:hemoglobin A1c protein, human