Exploring functional and structural vascular changes in obesity: are metabolically healthy obese individuals really healthy?

Abstract

Abstract Purpose Aim of the study is to compare vascular function and structure parameters among middle-aged men with differences in body mass index (BMI) and metabolic status and to investigate whether obese individuals with a normal metabolic profile have a unhealthy vascular profile. Methods We measured carotid-femoral pulse wave velocity (cfPWV), carotid intima media thickness (cIMT) and brachial flow-mediated dilation (bFMD) in 141 obese (BMI≥30 kg/m2) and in 176 aged-matched men with normal BMI (<25 kg/m2) individuals. All participants had no clinical manifestations or a history of atherosclerotic disease. High sensitivity C-reactive protein (hsCRP) and total testosterone (TT) were measured in all patients. Results The two BMI groups were subdivided into subgroups according to presence/absence of abnormal metabolic profile (presence of major cardiovascular risk factors): Metabolically unhealthy obese (MeUO, n=114), metabolically healthy obese (MeHO, n=27), metabolically unhealthy with normal BMI (MeUN, n=122) and metabolically healthy with normal BMI individuals (MeHN, n=54). The four subgroups had similar age. Figure 1 shows the mean cIMT (left plot), cfPWV (middle plot) and bFMD (right plot) of the four subgroups. Carotid IMT and cfPWV is higher and bFMD is lower in metabolically unhealthy compared to individuals with a normal metabolic profile in both patients with obesity and subjects with normal BMI. Interestingly, the MeNO patients had significantly lower cIMT (P<0.05) and cfPWV (P<0.01) and higher bFMD (P<0.01) level compared to MeUN individuals. However, as figure shows all measured vascular parameters were significantly impaired in MeNO patients compared to those of MeHN individuals. MeHO patients had comparable hsCRP and TT levels to those of MeUO and MeUN individuals denoting increased inflammatory activation and endogenous androgen deficiency. Conclusions MeHO which is a obesity phenotype that has created lot of debate is associated with a better vascular profile compared to MeUN status, however patients with MeHO have more impaired vascular function and structure parameters than MeHN individuals. This finding implies that even in the absence of overt metabolic aberrations, the MeHO profile may be associated with endothelial dysfunction, increased aortic stiffness and thickness of the carotid arterial wall. Figure 1. BMI, metabolic status and vascular changes Funding Acknowledgement Type of funding source: None