Clinical analysis of the serum muscle enzyme spectrum of patients with newly diagnosed Sheehan's syndrome.

We investigated the factors associated with serum muscle enzyme elevation in patients with Sheehan's syndrome. A total of 48 patients who were newly diagnosed with Sheehan's syndrome were included and divided into 3 groups: Group 1, creatine kinase (CK) ≥ 1000 U/L; Group 2, 140 < CK < 1000 U/L; and Group 3, CK ≤ 140 U/L. Differences in serum muscle enzymes, serum electrolytes, blood glucose and hormones were compared among the 3 groups. A Spearman correlation analysis and multiple linear regression analysis were performed on serum muscle enzymes and the other variables. Four patients in Group 1 underwent electromyography. Fourteen, 26 and 8 patients were divided into Group 1, Group 2, and Group 3, respectively. The levels of plasma osmolality, serum sodium, free triiodothyronine (FT3) and free thyroxine (FT4) in Group 1 were lower than those in Group 3 at admission (P < .05). There were significant differences in CK, CK-MB, aspartate aminotransferase, lactate dehydrogenase, and alpha-hydroxybutyrate dehydrogenase among the three groups (P < .05). CK was correlated with serum sodium (r = -0.642, P < .001), serum potassium (r = -0.29, P = .046), plasma osmolality (r = -0.65, P < .001), FT3 (r = -0.363, P = .012), and FT4 (r = -0.450, P = .002). Moreover, creatine kinase isoenzyme-MB (CK-MB) was correlated with serum sodium (r = -0.464, P = .001) and plasma osmolality (r = -0.483, P < .001). The multiple linear regression showed that serum sodium was independently and negatively correlated with CK (r = -0.352, P = .021). The electromyogram results supported the existence of myogenic injury. Sheehan's syndrome is prone to be complicated by nontraumatic rhabdomyolysis, with both a chronic course and acute exacerbation. Serum muscle enzymes should be routinely measured. For patients with CK levels > 1000 U/L, a CK-MB/CK ratio < 6% can be a simple indicator to differentiate rhabdomyolysis from acute myocardial infarction. Abnormal serum muscle enzymes observed in Sheehan's syndrome may be associated with hypothyroidism and with hyponatremia in particular.