Cognitive Function and the Risk for Diabetes Among Young Men

Abstract

OBJECTIVEDiabetes is a risk factor for an accelerated rate of cognitive decline and dementia. However, the relationship between cognitive function and the subsequent development of diabetes is unclear. RESEARCH DESIGN AND METHODSWe conducted a historical-prospective cohort study merging data collected at premilitary recruitment assessment with information collected at the Staff Periodic Examination Center of the Israeli Army Medical Corps. Included were men aged 25 years or older without a history of diabetes at the beginning of follow-up with available data regarding their general intelligence score (GIS), a comprehensive measure of cognitive function, at age 17 years. RESULTSAmong 35,500 men followed for a median of 5.5 years, 770 new cases of diabetes were diagnosed. After adjustment for age, participants in the lowest GIS category had a 2.6-fold greater risk for developing diabetes compared with those in the highest GIS category. In multivariable analysis adjusted for age, BMI, fasting plasma glucose, sociogenetic variables, and lifestyle risk factors, those in the lowest GIS category had a twofold greater risk for incident diabetes when compared with the highest GIS category (hazard ratio 2.1 [95% CI 1.5-3.1]; P < 0.001). Additionally, participants in the lowest GIS category developed diabetes at a mean age of 39.5 6 4.7 years and those in the highest GIS group at a mean age of 41.5 6 5.1 years (P for comparison 0.042). CONCLUSIONSThis study demonstrates that in addition to a potential causal link between diabetes and enhanced cognitive decline, lower cognitive function at late adolescence is independently associated with an elevated risk for future diabetes.Evidence from the last several years suggests that dysglycemia accelerates the rate of cognitive decline and increases the risk for dementia. Indeed, people with diabetes are about 1.5-fold more likely to experience an accelerated rate of cognitive decline and are twice as likely to develop dementia (1-4). It also has been shown that dysglycemia per se is associated with an increased risk for dementia (5). This relationship is partially explained by cardiovascular risk factors, education, socioeconomic status (SES), and lifestyle factors. However, common mechanistic pathways such as inflammation, microvascular disease, and the effects of insulin sensitivity on the brain and in the periphery have also been hypothesized as an explanation for this relationship.

Cognitive Performance at Late Adolescence and the Risk for Impaired Fasting Glucose Among Young Adults

“…Socioeconomic status (SES) data based on place of residence were obtained from records of the Israeli Ministry of Interior, which is coded on a scale of 1 to 10 based on the Israeli Central Bureau of Statistics. This scoring system stratifies all municipalities into 10 ranks taking into account variables that might affect SES (7). SES was coded into three groups: low (SES, 1-4), medium (SES, 5-7) and high (SES, 8 -10) as reported previously (26).…”

Sleep quality and risk of diabetes and coronary artery disease among young men

“…First, socioeconomic status and poor diet are associated with increased risk of both diabetes and sleep disturbances and therefore were suggested as potential confounders for such an association [27,28]. However, all participants of the MELANY study had equal access to free medical services and similar nutritional exposure during working hours with only modest effect of socioeconomic status on diabetes risk in this cohort [19,21]. These characteristics of the cohort, minimized potential bias due to differences in socioeconomic status, but did not eliminate it.…”

“…For the interaction model, BMI was categorized as normal (\25 kg/m 2 ) and overweight-obese (C25 kg/m 2 ), whereas glycemic status was categorized as normoglycemic (FPG \ 100 mg/dL) and impaired fasting glucose (100 B FPG \ 126 mg/dL). Country of origin (classified by the father's or grandfather's country of birth) was categorized into five geographical areas: former USSR countries, Asia (non-USSR), Africa (excluding South Africa), Western (comprised of non-USSR Europe, North and South America, South Africa, Australia and New Zealand) and Israel [19,21]. Subjects with missing data were excluded from multivariable analysis (model 2, 8.1 %; model 3, 11.6 %).…”

“…We previously reported that incident cases of diabetes in this cohort are mostly ([98 %) of type 2 diabetes [19].…”

Diabetes und Gehirn

“…Tab. 3: Auf methodische Probleme von Querschnittsstudien und prospektiven Kohortenstudien, die eine kausale Beziehung zwischen Diabetes und Demenz postulieren, weisen 2 aktuelle Studien [41,47] hin. Hier zeigte sich, dass die Richtung der Kausalität auch bidirektional sein kann.…”