Cognitive impairment is correlated with insulin resistance degree: the "PA-NICO-study".

Several epidemiological studies have shown that Diabetes Mellitus (DM) or Insulin Resistance (IR) increases the risk of dementia. Besides, some authors suggested that poor glucose control to be associated with worse cognitive function. We aimed to assess cognitive functions and IR-degree over time in diabetic. We also evaluated whether a greater magnitude of cognitive decline could be related with their IR degree. We enrolled 335 diabetic patients and 142 non-diabetic subjects; participants were subdivided into three groups in accordance with their IRdegree assessed by Homa-Index (HI): Normal-HI (non-diabetic NHI < 2,6), Moderate-HI (MHI > 2,6 < 10) and High-HI (HHI > 10). Metabolic status and a comprehensive neuropsycological test battery (MMSE, ADAS-Cog, ACDS-ADL) were assessed at baseline and every 12-months during the follow-up (6,8 years). At the end of the study, the average MMSE decreased significantly in patients of HHI group (P = .001) compared to baseline. MMSE scores were also reduced both in MHI group and in controls, but the difference between two groups was not significant. In HHI group, similar effects were observed for the ADAS-Cog score compared to baseline (P = 0.001); instead, when ACDS-ADL was evaluated, no differences was observed among the three groups. These results remained unchanged also after adjustment for confounding variables (i.e. APOε-status, sex, BMI, education level, heart diseases and HbA1c). We suggest that higher IR-degree is associated with greater cognitive decline in diabetic patients; so we hypothesize that IR degree, more than IR status itself, could be related to the severity of cognitive impairment.

Insulin resistance possible risk factor for cognitive impairment in fibromialgic patients.

To evaluate glucose metabolism and/or insulin resistance (IR) in 96 patients with Fibromyalgia (FM), associated or not to cognitive impairment. We investigated glucose metabolism in 96 FM patients. Enrolled patients were divided into two groups: 48 patients with memory deficit (group A) and 48 without memory deficit (control group). We evaluated glucose and insulin levels after a 2 h-Oral-Glucose-Tolerance-Test (2 h-OGTT) and insulin resistance (IR) by the homeostasis model assessment formula (HOMA). Body Mass Index (BMI), waist-to-hip-ratio (WHR), anxiety level, fasting plasma insulin and Non-Steroidal Anti-Inflammatory agents use were higher in patients with FM with memory impairment; while age, sex, waist circumference, education level, fasting plasma glucose, glycate hemoglobin, triglycerides, blood lipid profile, C- Reactivity-Protein (CRP), blood pressure and smoking habits were similar in both groups. Following OGTT the prevalence of glucose metabolism abnormalities was significantly higher in group A. IR was present in 79% patients, of whom 23% had also impaired glucose tolerance, 4% newly diagnosed diabetes mellitus and 52% IR only. Obesity and overweight prevailed in group A. IR, but not BMI or WHR was associated to an increased risk of memory impairment (OR = 2,6; 95% CI: 1,22-3,7). The results of this study suggest that IR may represent a risk factor for memory impairment in fibromialgic patients.