Glucose Metabolic Disorder in Klinefelter Syndrome: A Retrospective Analysis in a Single Chinese Hospital and Literature Review

Background: We aimed to investigate the clinical characteristics and islet β-cell function in patients with Klinefelter syndrome (KS) and hyperglycemia. Methods This is a retrospective study. There were 22 patients diagnosed of KS identified from electronic medical record system including 9 patients with hyperglycemia (THG-KS group). There were 5 hyperglycemic KS patients with oral glucose tolerance test (OGTT) results (HG-KS group), other 5 subjects with hyperglycemia and 5 euglycemic subjects matched in body mass index were included as HG group and NGT group, respectively. Clinical data and laboratory examinations were collected. We further performed a systematic literature review of KS and hyperglycemia. Results We found KS patients developed abnormal glucose metabolism earlier in life than those without KS. There were 35.3% patients diagnosed of DM and 17.6% patients diagnosed of prediabetes. Among 10 patients had both fasting blood glucose and insulin levels drawn, there were 47.1% patients with KS and insulin resistance. The incidence of hypertension and dyslipidemia were higher in patients with hyperglycemia and KS than euglycemic KS patients. Comparing with HG group, the level of insulin sensitivity was lower in HG-KS group, while the value of HOMA-β (p = 0.030) was significantly increased which indicated higher insulin secretion level in HG-KS group. Conclusions KS patients with hyperglycemia are more likely to combine other metabolic diseases. Compared with hyperglycemic patients without KS, they present lower insulin sensitivity and higher insulin secretion.