Secondary hyperparathyroidism Flashcards
what is the definition of SHPT?
SHPT is a complication of CKD and is important in the pathogenesis of CKD-mineral bone disorder (MBD).
what is the epidemiology of SHPT?
The estimated global prevalence of all-stage CKD in 2017 was around 9%. Over 80% of patients with CKD are at risk for the development of vitamin D deficiency, with an inverse correlation between decreasing 25-hydroxyvitamin D levels and elevated parathyroid hormone (PTH)
what is the epidemiology of SHPT?
Any disorder that results in hypocalcaemia will elevate parathyroid hormone (PTH) levels and can serve as a cause of SHPT.
The three principal aetiologies that may lead to this situation are chronic kidney disease (CKD), malabsorption syndromes, or chronic inadequate exposure to sunlight.
what are the risk factors for SHPT?
Ageing
CKD
Vit D deficient : nutritional, sunlight, malabsorption
what is the pathophysiology of SHPT?
Any deficiency in vitamin D causes a decrease in the efficiency of intestinal absorption of dietary calcium (and phosphorus). This results in a transient lowering of the ionised calcium, which promptly triggers increased production and secretion of PTH. PTH acts to increase ionised calcium in the blood by interacting with its membrane receptor on mature osteoblasts, which induces expression of RANKL.
what are the key presentations of SHPT?
Presence of risk factors
Features of CKD
Features of underlying malabsorption syndrome
what are the signs of SHPT?
Presence of risk factors Features of CKD Features of underlying malabsorption syndrome Chvostek’s sign Trousseau sign
what are the symptoms of SHPT?
Muscle cramps Bone pain Tingling in fingers and toes Bowed legs Fractures
what are the first line and gold standard investigations for SHPT?
Serum calcium - low
Serum intact PTH - high
Serum creatinine - high in CKD
Serum urea - high in CKD
what is the differential diagnosis for SHPT?
PHPT
how is SHPT managed?
Lack of sunlight:
UV radiation, Vit D supplements, calcium supplements
Malabsorption:
Managed underlying disease, UV, Vit D and calcium supplements
CKD:
Dietary phosphate restriction, phosphate binder, Vit D supplements, parathyroidectomy or calcimimetic
how is SHPT monitored?
Electrolytes, such as calcium, magnesium, and phosphorus, parathyroid hormone (PTH), and 25-hydroxyvitamin D levels should be monitored at a frequency appropriate for the underlying disease.
what are the complications of SHPT?
Renal osteodystrophy, osteoporosis, calciphylaxis
what is the prognosis of SHPT?
The outlook for patients with SHPT mirrors the underlying disease
