Browsing by Author "Natali, Andrea (57200684714)"

Aims/hypothesis: Experimental studies suggest that the fatty acid palmitoleate may act as an adipocyte-derived lipid hormone (or ‘lipokine’) to regulate systemic metabolism. We investigated the relationship of circulating palmitoleate with insulin sensitivity, beta cell function and glucose tolerance in humans. Methods: Plasma NEFA concentration and composition were determined in non-diabetic individuals from the Relationship between Insulin Sensitivity and Cardiovascular disease (RISC) study cohort at baseline (n = 1234) and after a 3 year follow-up (n = 924). Glucose tolerance, insulin secretion and beta cell function were assessed during an OGTT. Whole-body insulin sensitivity was measured by a hyperinsulinaemic–euglycaemic clamp (M/I) and OGTT (oral glucose insulin sensitivity index [OGIS]). The liver insulin resistance index was calculated using clinical and biochemical data. Body composition including fat mass was determined by bioelectrical impedance. Results: Circulating palmitoleate was proportional to fat mass (r = 0.21, p < 0.0001) and total NEFA levels (r = 0.19, p < 0.0001). It correlated with whole-body insulin sensitivity (M/I: standardised regression coefficient [std. β] = 0.16, p < 0.0001), liver insulin resistance (std. β = −0.14, p < 0.0001), beta cell function (potentiation: std. β = 0.08, p = 0.045) and glucose tolerance (2 h glucose: std. β = −0.24, p < 0.0001) after adjustment for age, sex, BMI, adiposity and other NEFA. High palmitoleate concentrations prevented the decrease in insulin sensitivity associated with excess palmitate (p = 0.0001). In a longitudinal analysis, a positive independent relationship was observed between changes in palmitoleate and insulin sensitivity over time (std. β = 0.07, p = 0.04). Conclusions/interpretation: We demonstrated that plasma palmitoleate is an independent determinant of insulin sensitivity, beta cell function and glucose tolerance in non-diabetic individuals. These results support the role of palmitoleate as a beneficial lipokine released by adipose tissue to prevent the negative effects of adiposity and excess NEFA on systemic glucose metabolism. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.

OBJECTIVE: We tested whether men and women in the European Society of Hypertension (ESH) high normal and normal blood pressure (BP) categories, all included in the the Seventh Joint National Committee (JNC 7) prehypertension group, share similar metabolic characteristics and whether they differ from men and women with optimal BP (<120/80 mmHg). METHODS: BP (multiple measurements with a standardized automatic device), insulin sensitivity (euglycaemic clamp), oral glucose tolerance test (OGTT), carotid intimaĝ€"media- thickness (IMT, echo), family history (questionnaire), physical activity (accelerometer), and anthropometrics (bioimpedance) were evaluated in the 1384 healthy European individuals ranging from 30ĝ€"60 years participating in the multicentre study Relationship between Insulin Sensitivity and Cardiovascular disease (RISC). RESULTS: BMI and waist-to-hip ratio were higher (both P < 0.05 adjusted for age and recruiting centre) in men and women with high normal (but not normal) BP with respect to optimal BP. Similarly, in women (after adjustment for study centre, age, physical activity, and waist), serum triglycerides and carotid IMT were higher in those with high normal (but not normal) BP; moreover, in this group there was a higher prevalence of glucose-intolerance (21.8 versus 9.7%, P ≤ 0.02) and insulin sensitivity tended to be lower (P ≤ 0.07). Insulin sensitivity and diastolic blood pressure were weakly related variables displaying a nonlinear association with a threshold below the normal BP values and no interaction with family history of hypertension. CONCLUSION: The JNC 7 category prehypertension identifies a dishomogeneous group of individuals whereas the ESH classification, particularly in women, was more accurate in identifying both the predisease and the healthy phenotype. Insulin resistance is not a major characteristic of the condition of prehypertension. © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins.

OBJECTIVE: We tested whether men and women in the European Society of Hypertension (ESH) high normal and normal blood pressure (BP) categories, all included in the the Seventh Joint National Committee (JNC 7) prehypertension group, share similar metabolic characteristics and whether they differ from men and women with optimal BP (<120/80 mmHg). METHODS: BP (multiple measurements with a standardized automatic device), insulin sensitivity (euglycaemic clamp), oral glucose tolerance test (OGTT), carotid intimaĝ€"media- thickness (IMT, echo), family history (questionnaire), physical activity (accelerometer), and anthropometrics (bioimpedance) were evaluated in the 1384 healthy European individuals ranging from 30ĝ€"60 years participating in the multicentre study Relationship between Insulin Sensitivity and Cardiovascular disease (RISC). RESULTS: BMI and waist-to-hip ratio were higher (both P < 0.05 adjusted for age and recruiting centre) in men and women with high normal (but not normal) BP with respect to optimal BP. Similarly, in women (after adjustment for study centre, age, physical activity, and waist), serum triglycerides and carotid IMT were higher in those with high normal (but not normal) BP; moreover, in this group there was a higher prevalence of glucose-intolerance (21.8 versus 9.7%, P ≤ 0.02) and insulin sensitivity tended to be lower (P ≤ 0.07). Insulin sensitivity and diastolic blood pressure were weakly related variables displaying a nonlinear association with a threshold below the normal BP values and no interaction with family history of hypertension. CONCLUSION: The JNC 7 category prehypertension identifies a dishomogeneous group of individuals whereas the ESH classification, particularly in women, was more accurate in identifying both the predisease and the healthy phenotype. Insulin resistance is not a major characteristic of the condition of prehypertension. © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins.