Difference between hypoparathyroidism and hyperparathyroidism
Answers
Primary hyperparathyroidism, a common endocrine disorder, is traditionally defined by hypercalcemia and an elevated or inappropriately normal PTH concentration. A newer presentation of primary hyperparathyroidism has been described in which serum calcium is normal and PTH is elevated in the absence of secondary causes of hyperparathyroidism, such as renal disease or vitamin D deficiency (1–6). Recognition of this phenotype of primary hyperparathyroidism, normocalcemic primary hyperparathyroidism, supports a biphasic chronological time course, in which PTH levels are first elevated but serum calcium is normal, followed by the development, in some, of frank hypercalcemia. Although normocalcemic primary hyperparathyroidism was recognized by the Third International Workshop on the Management of Asymptomatic Primary Hyperparathyroidism in 2008 (7), little is known about its epidemiology or natural history. The descriptions of normocalcemic primary hyperparathyroidism are confounded among the various studies published to date by differing methods to exclude secondary hyperparathyroidism (8–11). Moreover, reports of normocalcemic primary hyperparathyroidism have come largely from referral centers in which subjects were seen for a suspected metabolic bone disease (12–15). For example, among 37 individuals who were referred to a metabolic bone disease unit and subsequently diagnosed with normocalcemic primary hyperparathyroidism, 57% had osteoporosis by bone mineral density (BMD) T-scores <−2.5, 11% had documented fragility fractures, and 14% had nephrolithiasis (10). These individuals were thus more symptomatic than the typical cohort of patients with hypercalcemic primary hyperparathyroidism (16). These studies, although defining a new phenotype of primary hyperparathyroidism, could not give insight into how frequently community-dwelling individuals would be identified if not part of a referral population.
In contrast to primary hyperparathyroidism, hypoparathyroidism is a disease characterized by hypocalcemia and abnormally low or absent PTH levels. Hypoparathyroidism occurs primarily as an autoimmune disorder or after neck surgery. Permanent postoperative hypoparathyroidism has been reported in 2% to 13% of patients after total thyroidectomy (17). Progressive loss of parathyroid function may occur over months to years (18). In the context of previous surgical damage or autoimmune destruction of the parathyroid glands, it follows that there may be a first phase of the disease in which the serum calcium level is maintained but that the PTH levels are low, forming a pathophysiological counterpart to normocalcemic primary hyperparathyroidism. This phase is not likely to be recognized because PTH levels are rarely measured when the serum calcium concentration is normal. Up to now, the discovery of normocalcemic or subclinical hypoparathyroidism has been primarily in the context of hypocalcemia, sometimes life-threatening, after bisphosphonate administration to patients not previously recognized to have inadequate parathyroid gland reserves (19–22). To our knowledge, there has never been a formal investigation of the prevalence of normocalcemic hypoparathyroidism. In particular, no study has focused upon a community-dwelling population that is not suspected of an underlying metabolic bone disease.
We hypothesized that screening unselected, nonreferral community-dwelling populations, such as The Osteoporotic Fractures in Men (MrOS) study and Dallas Heart Study (DHS), would identify asymptomatic subjects with normocalcemic primary hyperparathyroidism and normocalcemic hypoparathyroidism. Recognizing these 2 populations with subclinical hyper- or hypoparathyroidism would significantly advance our understanding of the spectrum and development of parathyroid disease.
Hypoparathyrodisim...
- it is the state in which parathyroid hormone is less secreted than the normal quantity.
- In such condition blood calcium level is decreased and blood phosphorus level is increased.
- hypoparathyroidism during pregnancy causes deaf mutisam
Hyperparathyroidism...
- It is the state in which parathyroid hormone is more secreted than the normal quantity
- In such condition blood calcium level is increased and blood phosphrous level is decreased.