Differences in carbohydrate tolerance in Turner syndrome depending on age and karyotype

Abstract

Carbohydrate homeostasis was evaluated in 47 girls with Turner syndrome and in 25 "short normal" girls by means of an oral glucose tolerance test. Of the Turner patients 34% showed an impaired glucose tolerance vs 8% of the controls (chi 2 = 5.9, P less than 0.05). Mean glucose levels were significantly higher and mean insulin levels and insulinogenic index significantly lower in young Turner patients aged 5-12 years but not in adolescents aged 12-16 years. In both groups of patients, insulin levels and the insulinogenic index were significantly lower than those of the controls. In Turner patients between 12 and 16 years, carbohydrate tolerance improved and this may be explained by the lack of oestrogen release in these patients. Glucose tolerance was normal in patients with mosaicism. We conclude that (1) carbohydrate tolerance is defective in young children with Turner syndrome but improves in puberty due to the almost complete absence of oestrogen-progestogen secretion; (2) a difference in carbohydrate tolerance is evident depending on karyotype.

Insulin Resistance in a Patient with Diabetes Mellitus Associated with Turner's Syndrome.

“…Abnormalcarbohydrate metabolism in Turner's syndrome is caused by a diminished beta cell function and peripheral insulin resistance (1 , 2). However, impaired glucose tolerance in Turner's syndrome is believed to be caused by Turner's syndrome itself, as an abnormal oral glucose tolerance test and impairment of insulin-stimulated glucose uptake are more commonin nondiabetic children with Turner's syndrome than in normal children (3,8). However, the precise mechanism of insulin resistance in Turner's syndromehas not been clarified.…”

“…Diabetes mellitus associated with Turner's syndromeis a cytogenetic disorder, but its etiology has not been clarified (1)(2)(3). Turner' s syndrome is associated with an increased incidence of carbohydrate intolerance, and aging and obesity increase the incidence of diabetes mellitus associated with Turner's syndrome.…”

Avaliação da resistência insulínica e do perfil lipídico na síndrome de turner

“…Destas três pacientes, uma já foi descrita e discutida anteriormente, e as outras duas não eram obesas e apresentavam-se com valores normais de triglicérides, porém uma com colesterol total de 228mg% e LDL de 176mg% e outra, respectivamente, com 187mg% e 110mg%. De acordo com outros estudos, observou-se associação de resistência insulíni-ca e reposição estrogênica (7,8,(44)(45)(46).…”

“…A descrição de resistência insulínica na ST tem sido freqüentemente associada às mulheres adultas, obesas e com reposição estrogênica (7,8,(44)(45)(46) ou com o tratamento com hormônio de crescimento recombinante humano (35,36,47,48). Portanto, neste estudo, não se observou uma freqüência maior de resistência insulínica possivelmente devido ao pequeno número de mulheres adultas avaliadas, com baixa prevalência de obesidade, sem tratamento com hormônio de crescimento, e grande parte delas ainda sem a completa reposição estrogênica.…”

“…(45), que encontraram resistência insulínica apenas nas pacientes portadoras de cariótipo sem mosaicismo.…”