Endocrine disorders such as Cushing’s syndrome and hypothyroidism may cause weight gain and exacerbate metabolic dysfunction in obesity. Other forms of endocrine dysfunction, particularly gonadal dysfunction (predominantly testosterone deficiency in men and polycystic ovarian syndrome in women), and abnormalities of the hypothalamic-pituitary-adrenal axis, the growth hormone-IGF-1 system and vitamin D deficiency are common in obesity. As a result, endocrinologists may be referred people with obesity for endocrine testing and asked to consider treatment with various hormones. A recent systematic review and associated guidance from the European Society of Endocrinology provide a useful evidence summary and clear guidelines on endocrine testing and treatment in people with obesity. With the exception of screening for hypothyroidism, most endocrine testing is not recommended in the absence of clinical features of endocrine syndromes in obesity, and likewise hormone treatment is rarely needed. These guidelines should help reduce unnecessary endocrine testing in those referred for assessment of obesity and encourage clinicians to support patients with their attempts at weight loss, which if successful has a good chance of correcting any endocrine dysfunction.
John P H Wilding
Victoria S Sprung, Kelly A Bowden Davies, Juliette A Norman, Andrew Thompson, Katie L Mitchell, John P H Wilding, Graham J Kemp and Daniel J Cuthbertson
Data suggest that metabolic health status, incorporating components of metabolic syndrome (MetS), predicts cardiovascular disease (CVD) risk better than BMI. This study explored the association of MetS and obesity with endothelial function, a prognostic risk factor for incident CVD.
Forty-four participants were phenotyped according to BMI as non-obese vs obese (<30 or >30 kg/m2) and according to the International Diabetes Federation criteria of MetS: ≤2 criteria MetS (MetS−) vs ≥3 criteria MetS (MetS+); (1.)non-obese MetS− vs (2.) non-obese MetS+ and (3.) obese MetS− vs (4.) obese MetS+. Flow-mediated dilation (FMD), body composition including liver fat (MRI and spectroscopy), dietary intake, intensities of habitual physical activity and cardio-respiratory fitness were determined. Variables were analysed using a one-factor between-groups ANOVA and linear regression; mean (95% CI) are presented.
Individuals with MetS+ displayed lower FMD than those with MetS−. For non-obese individuals mean difference between MetS+ and MetS− was 4.1% ((1.0, 7.3); P = 0.004) and obese individuals had a mean difference between MetS+ and MetS− of 6.2% ((3.1, 9.2); P < 0.001). Although there was no association between BMI and FMD (P = 0.27), an increased number of MetS components was associated with a lower FMD (P = 0.005), and after adjustment for age and sex, 19.7% of the variance of FMD was explained by MetS, whereas only 1.1% was explained by BMI.
In this study cohort, components of MetS, rather than obesity per se, contribute to reduced FMD, which suggests a reduced bioavailability of nitric oxide and thus increased risk of CVD.