High Prevalence Of Altered Glucose Metabolism
In Young Adults With Prader-Willi Syndrome 

A. Crinò¹, P. Ciampalini¹, R. Schiaffini¹, A. Sartorio², G. Grugni²

¹Unit of Autoimmune Endocrine Diseases, Bambino Gesù Hospital, Piazza S. Onofrio 4 – 00165 Rome, ITALY ,  ²Division of Auxology, IRCCS S. Giuseppe Hospital, Italian Auxological Institute Foundation, Verbania - ITALY. 

Introduction: There are several data indicating reduced glucose tolerance in patients with Prader-Willi syndrome (PWS) (1). Among individuals with PWS it has been reported a prevalence of diabetes mellitus ranging from 17% to 41%. The differing rates of diabetes may depend on differences in age and body weight between the study groups. Moreover, this heterogeneity could result from a poor selection of the patients. In fact, the majority of the studies on the glucose tolerance were performed before the genetics of PWS had been delineated, particularly in older patients. The present study was designed to investigate the prevalence of abnormal glucose tolerance in a large group of young adults with PWS.

Patients and methods: Fifty-four patients, 22 males and 32 females, that met Holm criteria for genetically confirmed PWS, were included in the study: 

Fasting glucose and fasting insulin were determined in all patients. After an overnight fast, all the subjects with basal glycemia < 126 mg/dl underwent a standard 75g 120-minute oral glucose tolerance test. Glucose response was analyzed in according to the literature (2).

Results: Nine patients (12.7%) (4 males, 5 females, aged 23.9±0.7 yrs) were affected by diabetes mellitus, while 5 subjects (9.1%) (3 males, 2 females, aged 25.0±0.4 yrs) had an impaired glucose tolerance. Finally, 3 patients had only elevated fasting insulin levels (> 25 mcU/ml).

Conclusions: Our data show an abnormal glucose tolerance in 14 out of 54 (25.9%) adult subjects with PWS. Nevertheless, the high prevalence of impaired glucose metabolism may be secondary to the large proportion of PWS patients with grossly obesity rather than a feature of the syndrome itself. Further investigations are needed to better define the pathophysiology of altered charbohydrate metabolism in adult PWS.

References:

(1) Glucose homeostasis in Prader-Willi syndrome and potential implication of growth hormone therapy. Acta Paediatr Suppl. Dec; 88(433): 115-7, 1999

(2) Report of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Diabetes Care 1997;20:1183-1197.

July 2003