OGTT Glucose Response Curves, Insulin Sensitivity, and β-Cell Function in RISE: Comparison Between Youth and Adults at Randomization and in Response to Interventions to Preserve β-Cell Function
figure
posted on 2021-01-12, 23:37 authored by Silva Arslanian, Laure El ghormli, Joon Young Kim, Ashley H. Tjaden, Elena Barengolts, Sonia Caprio, Tamara S. Hannon, Kieren Mather, Kristen Nadeau, Kristina M. Utzschneider, Steven E. Kahn, The RISE Consortium<b>Objective:</b> We examined the
glucose-response-curves [<b><u>B</u></b>i<b><u>ph</u></b>asic (BPh), <b><u>M</u></b>ono<b><u>ph</u></b>asic
(MPh),
<b><u>I</u></b>ncessant-<b><u>In</u></b>crease (IIn)], during an oral
glucose tolerance test (OGTT), and their relationship to insulin sensitivity
(IS) and b-cell function (bCF) in youth vs. adults with IGT or recently diagnosed type 2
diabetes.
<p><b>Research Design and Methods:</b> This was both a cross-sectional and
longitudinal evaluation of participants in the RISE study randomized to
metformin alone for 12 months or glargine for 3 months followed by metformin
for 9 months. At baseline/randomization, OGTTs (85 youth, 353 adults) were categorized
as BPh, MPh, or IIn. The relationship of the glucose-response-curves to hyperglycemic-clamp-measured
IS and bCF at baseline, and the change in glucose-response-curves 12 months after randomization were
assessed. </p>
<p><b>Results:</b> At randomization, the prevalence of
the BPh-curve was significantly higher in youth than adults (18.8%
vs. 8.2%), with no differences in MPh or IIn. IS did not differ across glucose-response-curves
in youth or adults. However, irrespective of curve type, youth had lower IS
than adults (p<0.05). bCF was lowest in IIn vs. MPh and BPh in
youth and adults (p <0.05). Yet, compared with adults, youth had higher bCF in BPh and MPh (p<0.005), but not IIn
curves. At month 12, the change in glucose-response-curves did not differ
between youth and adults, and there was no treatment effect. </p>
<p><b>Conclusions:</b> Despite a 2-fold
higher prevalence of the more-favorable BPh curve in youth at randomization, RISE
interventions did not result in beneficial changes in glucose-response-curves
in youth compared with adults. Moreover, the typical b-cell hypersecretion in youth was not
present in the IIn curve, emphasizing the severity of b-cell dysfunction in youth with this least-
favorable glucose-response-curve.</p>
