Lower insulin sensitivity as an independent risk factor for carotid wall thickening in normotensive, non-diabetic, non-smoking normal weight and obese premenopausal women

Abstract

OBJECTIVE: Increased thickness of the intima ± media complex of the common carotid artery (IMT-CCA) is an early marker of atherosclerosis. The aim of the present study was to investigate the relationship between insulin resistance and IMT-CCA in premenopausal women. SUBJECTS: 86 young women, aged 18 ± 31 y, were recruited for the study: 28 were normal weight (BMI`25 kgam 2 ), 23 were overweight (BMI 25 ± 30 kgam 2 ) and 35 were obese (BMI b 30 kgam 2 ). MEASUREMENTS: The IMT-CCA was measured by high resolution`B-mode' ultrasonography; insulin sensitivity was determined by insulin tolerance test (ITT) and quantitated by calculation of K ITT. Fasting plasma glucose and lipids (triglycerides, total and HDL-cholesterol) were also measured by enzymatic methods. Central fat accumulation was evaluated by measuring waist circumference (WC). RESULTS: IMT-CCA showed an inverse association with K ITT (P`0.05). When the IMT-CCA was considered as the dependent variable in a forward stepwise multiple regression analysis, it maintained an independent association with K ITT (P`0.05), after adjusting data for age, BMI, WC, mean blood pressure levels and plasma glucose and lipids. CONCLUSION: These results suggest that IMT-CCA is signi®cantly associated with insulin resistance, independent of other well-known CVD risk factors. Since the IMT-CCA is an earlier asymptomatic sign of atherosclerosis, this study indicates that insulin resistance per se may accelerate atherogenesis.

Body composition and fat repartition in relation to structure and function of large arteries in middle-aged adults (the SU.VI.MAX study)

“…In our study, WC but not WHR was positively associated with IMT. Positive associations between WC and IMT have been observed in some 8,10,26 but not all 9,15,18 studies.…”

“…The observed positive relationship of BMI with CCA-IMT is in agreement with results of many previous studies. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] This association is usually taken as indirect evidence of a relationship of body fat content with this early atherosclerosis marker. Interestingly, our results show positive associations of both FM and FFM, independent of each other, with CCA-IMT.…”

Free testosterone plasma levels are negatively associated with the intima-media thickness of the common carotid artery in overweight and obese glucose-tolerant young adult men

“…34,35 However, after multivariate analysis, IMT-CCA maintained an independent association only with FM (or BMI) and FT, thus definitely showing that body fatness per se has a deleterious effect on the development of the atherosclerotic process. At variance with our previous findings, 36 insulin resistance was not associated with the thickness of the arterial wall.…”

Effect of shift work on body mass index: results of a study performed in 319 glucose-tolerant men working in a Southern Italian industry

“…The importance of these findings derives from the fact that both body fatness and insulin resistance accelerate the development of atherosclerosis independently of each other. 37,38 On the other hand, insulin levels were significantly associated with BMI, but not with shift work. Therefore, in our opinion, it seems possible that shift work is responsible for higher BMI and, in turn, higher body fatness causes insulin sensitivity to decrease and glucose metabolism to be altered.…”