Background. This report focuses on the glycemic stale in relation to insuli
n and lipid levels of a cohort of elderly hypertensive persons to estimate
the prevalence of syndrome X.
Methods. ii cross-sectional study was performed at the University of Tennes
see, Memphis, and the General Clinical Research Center (GCRC) on 95 partici
pants in the Trial of Nonpharmacologic Interventions in the Elderly (TONE)
study who agreed to participate in an ancillary study. A standard oral gluc
ose tolerance test (OGTT) with insulin and C-peptide levels and a fasting l
ipid profile were obtained.
Results. In this sample of healthy elderly participants with hypertension w
ho were taking an antihypertensive medication, 43 (45.3%) had normal glucos
e tolerance (NGT), 41 (43.2%) had impaired glucose tolerance (IGT), and 11
(11.6%) had undiagnosed non-insulin-dependent diabetes mellitus (NIDDM). Fa
sting hyperinsulinemia occurred in only one participant, who was in the IGT
group. Hypertriglyceridemia and low high density lipoprotein (HDL) occurre
d in four persons, none of whom had hyperinsulinemia. Persons in the NIDDM
and IGT groups had decreased beta cell function compared to persons in the
NGT group, but did not have increased peripheral insulin resistance as esti
mated from the OGTT data.
Conclusions. Our data demonstrated that in this cohort of elderly hypertens
ive participants with a high prevalence of central obesity, impaired glycem
ic control was common, but was not associated with Fasting hyperinsulinemia
or peripheral insulin resistance. Furthermore, we conclude that syndrome X
essentially did not occur in these participants and postulate that the pri
mary etiology fur their impaired glycemic control is beta cell dysfunction.
Further research is needed to elucidate these relationships.