A 72-year-old woman with long history of type-2 DM presents with abdominal pain. Physical examination reveals neuromuscular weakness and hypeension. Laboratory studies show markedly reduced serum calcium and elevated PTH. A surgical exploration of the patient's neck demonstrates 4 symmetrically enlarged parathyroid glands. This patient's endocrinopathy may be caused by which of the following underlying disorders?

- Given clinical features suggests the diagnosis of secondary hyper-parathyroidism Secondary hyper-parathyroidism -Depicted as CB Calcium ,| PTH - Causes: Chronic renal failure Vitamin D deficiency Intestinal malabsorption Fanconi syndrome -Diabetic glomerulosclerosis is a major cause of renal insufficiency. -Chronic hypocalcemia & retention of phosphate-Compensatory hypersecretion of PTH in renal failure. - As a result, secondary hyperplasia of all parathyroid glands occurs. Enlarged parathyroid glands occasionally become independently hyperfunctional resulting in teiary hyperparathyroidism. Primary hyperparathyroidism is caused by parathyroid adenoma/ hyperplasia/ carcinoma.