Hormone profile of patients referred for Bariatric surgery
Lakshminarayanan Varadhan, C V N Cheruvu, George Varughese & Richard Clayton
Aim: An increasing proportion of patients are referred to endocrine clinics for assessment of an endocrine reason for obesity. The aim of our study was to assess the hormone profiles of patients referred for bariatric surgery.
Methods: Patients referred to bariatric surgery clinic were investigated for hypothyroidism (TSH, T4), Cushings disease (2 mg-overnight dexamethasone suppression test), acromegaly (IGF1) and Vitamin D deficiency (PTH, Ca and Vitamin D) based on clinical suspicion. A retrospective observational analysis was conducted to analyse the prevalence of endocrine disorders and distribution of comorbidities.
Results: Demographics: n=159 patients; mean age: 42.6 years (1767); females: 80%; mean BMI 49.5 kg/m2 (3573).
Distribution of comorbidities: Clinical Diabetes mellitus: 30.2%, Hypertension: 37.7%, Dyslipidemia: 34%, Severe arthritis: 39%, Obstructive sleep apnoea: 6.3%.
Cushings syndrome: n=85; None of the patients had documented cushingoid morphology. Apart from one patient who had unsuppressed cortisol (=68 nmol/l; urinary free cortisol normal not investigated further), all the others were negative.
Thyroid status: n=159; 13% were known hypothyroidism on replacement; 33% of them were inadequately replaced. 1.4% had sub-clinical hypothyroidism not being treated so far.
Acromegaly: n=52; All had normal age-related IGF1 levels.
Bone: PTH: n=105; 61% had high PTH (>6.4 pmol/l). Serum calcium was within normal range in all patients. PTH values correlated positively to BMI (r=0.1). Vitamin D: n=81; 16.1% deficient (<10 μg/l); 60.5% were insufficient (1130 μg/l); 23.4% were Vitamin D replete (>30 μg/l). Vitamin D correlated negatively to BMI (r=−0.2).
Conclusion: A vast majority of patients with morbid obesity, who are referred for bariatric surgery, do not have an endocrine aetiology. Vitamin D deficiency or insufficiency is present in a high proportion of this cohort (77%) and hence should be treated prior to surgery and reassessed post-operatively. Thyroxine treatment should be optimized in patients with prior hypothyroidism. Screening for Cushings syndrome or acromegaly need not be performed unless clinically indicated.