LAUSR

In hypoparathyroidism, cardinal symptoms relate to hypocalcemia causing increased neuromuscular excitability with paresthesia’s, which in severe cases may develop into epileptiform seizures. Conventional treatment of hypoparathyroidism includes activated vitamin D analogues and calcium supplements that in most instances result in a normalized serum calcium and thereby reduces the burden of hypocalcemic symptoms. A number of recent studies, however, have documented that hypoparathyroidism is a complex disease which cannot be considered adequately treated just by archiving normocalcemia. Patients are at increased risk of a number of complications including renal insufficiency, psychiatric diseases, and infections. Furthermore, patients often have neurocognitive complains. Symptoms such as impaired ability to focus, concentration problems, and memory loss are collectively called “brain fog”. In this issue of Endocrine, Büttner et al. [1], highlights an additionally important complication to hypoparathyroidism in terms of a reduced quality of life (QoL). By performing a systematic literature review, Büttner et al. [1] identified five studies using validated questionnaires to assess QoL in patients with hypoparathyroidism. Three of the studies used the SF-36/ RAND36-Item Health Survey, all showing a lower QoL in patients with hypoparathyroidism compared with norm-based controls. Similarly, a reduced QoL was found in two studies comparing patients with matched healthy controls. Interestingly, QoL seems to be more reduced in patients with postsurgical hypo parathyroidism compared with non-surgical hypopara thyroidism. As many patients with non-surgical hypoparathyroidism have been born with the disease, it seems likely that patients who have acquired the diseases may feel more affected, as they know how they felt prior to being diseases. As reported by Büttner et al. [1], most patients with postsurgical hypoparathyroidism are also suffering from postsurgical hypothyroidism. It may therefore be questioned whether the impaired QoL is due to the co-existence of hypothyroidism. Although only limited data are available, patients with both hypoparathyroidism and hypothyroidism seem to have a larger impairment in QoL-scores than patients only suffering from hypothyroidism, suggesting that hypoparathyroidism independently of hypothyroidism contributes to an impaired QoL [2]. Interestingly, studies evaluating QoL have reported that both the mental and physical domains are affected, even though calcium levels in studied patients have been fairly well regulated. An impairment of physical function as determined by QoL measures is in good agreement with many patients complaining of muscular symptoms, as well as studies have shown a reduced muscle strength/function compared with healthy controls [2]. As correctly noted by Büttner et al. [1], conventional therapy with active vitamin D and calcium supplements does restore the physiological calcium/phosphorus homeostasis. In people with intact parathyroid function, serum calcium levels are tightly controlled. Although normocalcemia most often is archived by conventional therapy, patients are still unable to fine-tune their calcium homeostasis, and fluctuations in serum calcium may occur. This may sometimes be attributable to e.g., physiological stress such as exercise. However, fluctuations often occur unexpectedly and without any obvious reasons. Due to the importance of calcium on neuromuscular * Lars Rejnmark [email protected]