Body mass index and the risk of cancer incidence in patients with type 2 diabetes in Japan: Results from the National Center Diabetes Database

Abstract

Aims/IntroductionBoth type 2 diabetes and obesity increase the risk of some types of cancers, and underlying mechanisms are thought to be, at least in part, common. In the present study, we carried out a retrospective cohort study of the relationship between body mass index (BMI) categories and cancer development in Japanese type 2 diabetic patients.Materials and MethodsA total of 113 incident cancers including 35 cancers whose incidence was reported to be increased by obesity (27 colorectal cancers, two breast cancers in postmenopausal women, one endometrial cancer, four renal cancers and one gallbladder cancer) were identified in 2,334 type 2 diabetic patients (1,616 men and 718 women) over an average observation period of 5.1 years.ResultsIn men, there was no significant association between the BMI categories at the start of the observation period and the development of any cancer. In contrast, the incidence of all of the cancers in the women was significantly higher in the group with a BMI of less than 22.0 kg/m2 (hazard ratio 3.07, 95% CI 1.01–9.36). In either sex, there was no significant relationship between the BMI categories and the development of cancers whose risk is known to be increased by obesity.ConclusionsThe findings of the present study were limited by the relatively small number of patients in the cohort, which posed a danger of not finding significance. However, the results suggested that obesity did not become an additional risk factor for cancer in Japanese type 2 diabetic patients.

Association between body mass index and obesity-related cancer risk in men and women with type 2 diabetes in primary care in the Netherlands: a cohort study (ZODIAC-56)

“…A study from Japan could not find an association between BMI and all obesity-related cancers. 6 However, this was a study that included 2334 patients of whom only 35 patients developed cancer during follow-up. 6 …”

“…One previous study did not find an association between BMI and obesity-related cancers in T2D. 6 Another study investigated this association with colon cancer and found only a significant relationship in patients who suffered from obesity for a total duration of 4 years or more. 7 …”

Body mass index and cancer risk among Chinese patients with type 2 diabetes mellitus

“…However, the study did not include patients with BMI less than18.5 kg/m 2 . A study based on the Japan National Center Diabetes Database did not find a significant association between BMI categories and the risk of overall cancers and obesity-related cancers among male patients, but observed a significantly higher risk of overall cancer among female patients with BMI less than 22 kg/m 2 [ 19 ].…”

“…To evaluate the association of BMI with cancer risk among T2DM patients is another approach to better understanding the mechanisms that link obesity and diabetes with cancers. However, limited evidence is available on the association between BMI and cancer risks in patients with T2DM [ 19 , 20 ]. In this study, we conducted a large-scale retrospective cohort study based on the diabetes management database in Minhang district of Shanghai, China, to examine the association between BMI and risks of overall and site-specific cancers in Chinese diabetic patients.…”

Waist circumference, body mass index, and colorectal cancer risk according to diabetes status: A Korean nationwide population‐based cohort study

“…Consequently, the visceral adipose tissue may be more closely associated with CRC 25,26 . A recent study from Japan has also shown no significant association between BMI and risk of CRC 27 . This implies that waist circumference may be more important than BMI as a risk factor of CRC in Asian population.…”