Table 6.

Endocrine evaluation in a patient with obesity

Gland	Prevalence in obesity	When to assess	First diagnostic procedure	Other mandatory workup in obesity	Not recommended in obesity
Thyroid	Severe hypothyroidism is rare but subclinical hypothyroidism is common	Thyroid function should be tested in all patients with clinical suspicion of hypothyroidism, those having resistant obesity, and those undergoing procedures for weight loss	TSH	Free T4 and antibodies (anti-TPO) should be measured only if TSH is elevated	Routine FT3 in patients with elevated TSH; Routine ultrasound of the thyroid gland (irrespective of thyroid function)
Adrenal	Cushing’s disease or Cushing’s syndrome is rare	Central obesity; Hypertension; Classic striae Facial plethora; Proximal myopathy; Purpura	1 mg ODST	24-hr urine cortisol or late-night salivary cortisol in patients with positive 1 mg overnight dexamethasone suppression test; Imaging (find the cause/source) and ACTH in patients with confirmed hypercortisolism	Routine testing for hypercortisolism
	Drug-induced adrenal dysfunction (e.g., glucocorticoids) is common	Biochemical testing should be performed in patients with clinical suspicion of hypercortisolism; those undergoing bariatric surgery, or having psychiatric disorders	8 am cortisol		Testing for hypercortisolism in patients using corticosteroids
Male gonad	Androgen deficiency is common	Severe obesity; Symptoms and signs of hypogonadism	LH, FSH, fasting morning testosterone	Total and free testosterone (or calculated), SHBG in patients with clinical features of hypogonadism	Routine biochemical testing for hypogonadism unless key clinical symptoms or signs of hypogonadism
Female gonad	Androgen excess is common	Central obesity; Irregular menses; Hirsutism; Acanthosis nigricans chronic anovulation/infertility	LH, FSH, estradiol, testosterone	Total testosterone, SHBG, Δ 4androstenedione, 17-hydroxyprogesterone and prolactin in patients with menstrual irregularities (assess in early follicular phase if menstrual cycle is predictable)	Routine testing for gonadal dysfunction
		Clinical features of PCOS	Total testosterone, free T, Δ 4androstenedion, SHBG and blood glucose	Ovarian morphology
Pituitary	GH deficiency is rare	Hypothalamic or pituitary disease, pituitary or hypothalamic surgery or radiation therapy	IGF1/GH using a dynamic test only in patients with suspected hypopituitarism	Routine testing for IGF1/GH
	Hypopituitarism is rare	Suspicion of hypothalamic obesity; Surgery or radiotherapy in pituitary region	FT4 TSH LH FSH (testosterone or estradiol); GH IGF-1 PRL; ACTH stimulation test; GH stimulation test
	Acquired hypothalamic obesity (hypothalamic lesions or, tumors) is rare	Severe hyperphagia; Possible multiple endocrine abnormalities	Brain CT/MRI
Parathyroid	Pseudohypoparathyroidism type 1a (Albright hereditary osteodystrophy) is rare	Short stature, short fourth metacarpal bones, obesity, s.c. calcifications, developmental delay	PTH↑calcium↓phosphate ↑		Routine testing for hyperparathyroidism or Vitamin D deficiency
Syndromic obesity	Hypothalamic obesity associated with Genetic Syndromes is very rare	Hypogonadism (hypogonadism or hypergonadotropic) or variable gonadal function; dysmorphic syndrome, mental and grow retardation	Leptin (leptin resistance); genetic testing	Routine testing of hormones such as leptin and ghrelin in patients with suspicion of syndromic obesity

Abbreviations: ACTH, Adrenocorticotropic hormone; FSH, Follicle-stimulating hormone; FT4, Free thyroxine; GH, Growth hormone; IGF, Insulin-like growth factor; LH, Luteinizing hormone; MC4R, Melanocortin receptor 4; ODST, Overnight dexamethasone suppression test; PCSK, Proprotein convertase subtilisin/kexin; PTH, Parathyroid hormone; TSH, Thyroid-stimulating hormone