Review of the Recent Medical Literature

Glycemic Control and Cognitive Function
Older patients with diabetes are at increased risk for unrecognized cognitive dysfunction, depression, and functional disabilities. A group of 60 patients presenting to a geriatric diabetes clinic were screened for depression using the Geriatric Depression Scale and for cognitive dysfunction using the Mini-Mental State Examination, a clock-drawing test, and a clock-in-a-box test. The scores were low on these last 2 tests and were inversely correlated with hemoglobin A1c levels. One third of the patients had depressive symptoms. Poor glycemic control was also associated with high incidences of hearing and vision impairment and a history of recent falls.

Munshi M, et al. Cognitive dysfunction is associated with poor diabetes control in older adults. Diabetes Care. 2006;29:1794-1799.

Metabolic Syndrome Linked to Cancer
The metabolic syndrome was found to increase the risk of prostate cancer in a study of 15,993 men who were followed for 27 years. None had been diagnosed with diabetes or cancer when the study began. Metabolic syndrome was defined by body mass index, nonfasting glucose, triglycerides, and blood pressure or drug-treated hypertension. A combination of any 2 features of the syndrome was associated with a 23% increased risk for prostate cancer; having 3 features increased the risk by 56%. Independent risk factors for prostate cancer included age, body mass index, and sedentary occupations.

Lund Haheim L, et al. Metabolic syndrome predicts prostate cancer. Am J Epidemiol. 2006;164:769-774.

Hostility, Stress Predict Insulin Resistance
A study of 643 men (mean age, 63.1 years) who were not taking diabetes medications indicates that those with high levels of stress and hostility were more likely to have insulin resistance. Stress was determined by 24-hour urinary norepinephrine measurement; hostility was based on the Cook-Medley Hostility scale; and insulin resistance was defined by the homeostatic model assessment (HOMA) index, insulin levels, and 2-hour postchallenge glucose. After controlling for covariates, interaction between hostility and stress significantly predicted insulin resistance. At greater levels of stress, increased levels of hostility were significantly associated with a higher HOMA score (P <.05). Hostility was not a significant predictor of HOMA score at mean and lower levels of stress. Cynicism, but not other components of hostility, was found to be associated with stress and insulin resistance.

Zhang J, et al. Hostility and urine norepinephrine interact to predict insulin resistance. Psychosom Med. 2006;68:718-726.

Decaffeinated Coffee Lowers Diabetes Risk
Decaffeinated coffee consumption is inversely related to the development of type 2 diabetes, according to results from the Iowa Women’s Health Study of 28,812 postmenopausal women without diabetes or cardiovascular disease at baseline. At a mean follow-up of 11 years, compared with women who did not drink coffee, those who drank at least 6 cups/day had a 22% lower risk of type 2 diabetes. The decreased risk was 33% with decaffeinated coffee and 21% with regular coffee.

Pereira MA, et al. Coffee consumption and risk of type 2 diabetes mellitus. Arch Intern Med. 2006;166:1311-1316.

Self-Monitoring of Blood Glucose Not Useful
Self-monitoring of blood glucose (SMBG) does not help glycemic control in patients with type 2 diabetes, according to a cross-sectional study of 1286 patients with diabetes who were followed for 5 years. Overall, 70% of the patients reported SMBG at study entry. Greater use of SMBG correlated with shorter diabetes duration, getting diabetes education, taking insulin, and self-reporting hypoglycemic events. During follow-up, hemoglobin A1c levels were similar in SMBG users and nonusers, both overall and within diabetes treatment subgroups.

Davis WA, et al. Is self-monitoring of blood glucose appropriate for all type 2 diabetic patients? Diabetes Care. 2006;29:1764-1770.

Type 2 Diabetes and Risk of Colon Cancer
Men, but not women, with type 2 diabetes may be at greater risk of colorectal cancer, according to a retrospective study of 1975 persons who met standardized criteria for type 2 diabetes. During 19,158 person-years of follow-up, 51 new cases of colorectal cancer were identified compared with only 36.8 expected cases. The incidence ratio in men was 1.67 for any colorectal cancer and 1.96 for proximal cancer. Type 2 diabetes did not increase risk for colorectal cancer in women. Compared with never-smokers, the incidence ratio for colorectal cancer was 1.77 in current and former smokers; the interaction between type 2 diabetes and smoking status was significant.

Limburg PJ, et al. Clinically confirmed type 2 diabetes mellitus and colorectal cancer risk. Am J Gastroenterol. 2006;101:1872-1879.