A 28-year-old lady has put on weight (10 kg over a period of 3 years) and has oligomenorrhoea followed by amenorrhea for 8 months. The blood pressure is 160/100 mm of Hg. Which of the following is the most appropriate investigation?
Serum electrolytes Plasma cortisol Plasma testosterone and ultrasound evaluation of pelvis T3, T4 and TSH