First baseline data of the Klinefelter ItaliaN Group (KING) cohort: clinical features of adult with Klinefelter syndrome in Italy

J Endocrinol Invest. 2022 Sep;45(9):1769-1776. doi: 10.1007/s40618-022-01816-4. Epub 2022 May 24.

Abstract

Background: Klinefelter syndrome (KS) is frustratingly under-diagnosed. KS have a broad spectrum of clinical features, making it difficult to identify. OBJECTIVE: We describe KS clinical presentation in a large Italian cohort.

Design: This is the first observational cohort study within a national network, the Klinefelter ItaliaN Group (KING). Primary outcomes were to describe the basic clinical features and the actual phenotype of KS in Italy. Secondary outcomes were to determine age at diagnosis and geographical distribution.

Methods: We performed a basic phenotyping and evaluation of the hormonal values of 609 adult KS patients.

Results: Mean age at diagnosis was 37.4 ± 13.4 years. The overall mean testicular size was 3 ml, and 2.5 ml in both testes in untreated KS group. BMI was 26.6 ± 5.8 kg/m2, and 25.5% of KS had metabolic syndrome (MetS). LH and FSH were increased, and mean total testosterone were 350 ± 9.1 ng/dl. A descriptive analysis showed that 329 KS patients were evaluated in Northern Italy, 76 in Central and 204 in Southern Italy. Analysis of variance demonstrated significant statistical differences (p < 0001) between the age at diagnosis of the three geographical groups. Compared with the expected number among male patients matched for age in Italy, only 16% of KS patients received a diagnosis.

Conclusions: These data are the results of the only national database available that collects the clinical and hormonal data of the KS patients, currently referred at the KING centers. In Italy the typical KS patient is overweight, with small testes, and elevated LH and FSH. Only 25.5% of them are diagnosed with MetS. Early detection and timely treatment are mandatory.

Keywords: BMI; FSH; Klinefelter syndrome; LH; MetS; Metabolic syndrome; Testis; Testosterone.

Publication types

  • Observational Study

MeSH terms

  • Follicle Stimulating Hormone / therapeutic use
  • Humans
  • Hypogonadism* / drug therapy
  • Klinefelter Syndrome* / complications
  • Klinefelter Syndrome* / diagnosis
  • Klinefelter Syndrome* / epidemiology
  • Male
  • Metabolic Syndrome* / complications
  • Metabolic Syndrome* / diagnosis
  • Metabolic Syndrome* / epidemiology
  • Testis
  • Testosterone / therapeutic use

Substances

  • Testosterone
  • Follicle Stimulating Hormone