Diabetes could up risk of kidney cancer in non-obese women-Study

Diabetes could up risk of kidney cancer in non-obese women-Study

Diabetes increases the risk of kidney cancer in postmenopausal non-obese women, find a recent analysis from the Iowa Women’s Health Study (IWHS). The results are published online in journal Maturitas.

The women were defined as non-obese based on their body mass index (BMI) and waist circumference. Cutoffs used to define obesity included a BMI of 30 kg/m2, a waist-to-hip ratio (WHR) of 0.85, and a waist circumference of 34.6 inches.

Compared to women without diabetes, women with diabetes and a BMI < 30 kg/m2 had an 82% higher risk of kidney cancer, and those with diabetes and a waist circumference < 34.6 inches had an over two-fold greater risk.

“[While we found that] an association between diabetes and kidney cancer was not statistically significant among the whole cohort…a positive, statistically significant association was observed among nonobese women (BMI < 30 kg/m2) or waist circumference < 34.6 inches (87.9 cm),” the authors suggest.

The IWHS was launched in 1986 when a baseline questionnaire was completed by a total of 41,836 women..The cohort for the current analysis included 36,975 women, mean age of 61.7 years, 6.4% of whom reported a diabetes diagnosis at baseline.

The participants were enquired about the intake of anti-diabetes pills and/or insulin. Between 1986 and 2011, investigators identified 257 cases of kidney cancer in their cohort. The team saw an increased risk of kidney cancer increased for women with diabetes. Over the course of follow-up, an additional 8.5% of women reported a new diagnosis of diabetes.

The majority of diabetes cases in the study had type 2 diabetes (T2D). The T2D is associated with high blood glucose, which itself may increase uncontrolled cell growth and division, noted the researchers.

Patients with type 2 diabetes have high serum levels of insulin that promote the secretion and production of insulin-like growth factor 1 (IGF-1) that is important in the regulation of cell proliferation and differentiation, and thus may promote the formation and growth of cancer.

However, the researchers observed a nonlinear relationship between BMI and IGF-1 levels among the cohort. The team found that in some women IGF-1 concentrations increased as BMI increased up to a maximum of 26 kg/m2, after which IGF-1 concentrations decreased among women with higher BMIs.

“In line with this finding, we found an association among nonobese women even in the fully adjusted model..but observed no association between diabetes and kidney cancer among obese women…which could be explained by lower levels of IGF-1 among obese women.” pointed out the researchers.

The team suggested the need for validation of the findings in larger or pooled prospective studies. They stress that patients with new-onset diabetes may require more thorough surveillance for cancer including kidney cancer.