Pattern of body fat distribution may indicate dysglycemia in HIV patients
MedWire News: HIV infection is associated with higher 2-hour glucose and a higher prevalence of impaired glucose tolerance (IGT), say researchers.
This increase may be driven by differences in body fat distribution, suggests their study, published in the journal Diabetes Care.
The association between IGT and HIV infection remains unclear due to relatively little data being available to represent populations with these conditions, explain the authors.
Accordingly, Carl Grunfeld (University of California, San Francisco, USA) and colleagues analyzed data on 678 participants without previously diagnosed diabetes from the second examination of the Study of Fat Redistribution and Metabolic Change in HIV Infection (FRAM).
FRAM was designed to evaluate the prevalence and correlates of changes in fat distribution, insulin resistance, and dyslipidemia in a representative sample of HIV-infected and control participants in the USA.
The second FRAM examination was conducted 5 years later to re-evaluate 824 of the original participants. Of these, glucose tolerance testing (GTT) was included and 2-hour glucose levels were available for a total of 491 HIV-infected and 187 control participants.
The authors found that HIV-infected participants had higher 2-hour glucose levels (mean 108.9 mg/dl) compared with control participants (mean 101.3 md/dl).
IGT was found in 16.8% of HIV-infected participants and in 12.3% of control participants, and when individuals with IFG were excluded, a similar pattern was seen (13.1% versus 8.2%, respectively).
"Undiagnosed IGT may therefore be more common in the HIV-infected population," say the authors.
They also found that "regional body fat" significantly contributed to group differences in 2-hour glucose and IGT.
Mean 2-hour glucose values were 7.6 mg/dl higher in HIV-infected participants than in control participants and remained 7.3 mg/dl higher after demographic adjustment.
However, after further adjustment for adipose tissue (AT) volume the difference was attenuated to 4.3 mg/dl.
Further analysis revealed that higher upper trunk subcutaneous adipose tissue (SAT) and lower leg SAT were independently associated with higher 2-hour glucose values in both HIV-infected and control participants.
These body fat characteristics may identify HIV-infected patients with normal fasting glucose who are at increased risk for diabetes, suggest the authors.
"Loss of leg SAT is readily recognizable by most clinicians, and individuals with this finding may benefit from GTT even if fasting glucose is normal," write Grunfeld and team.
"Future studies should address physiologic mechanisms by which upper trunk SAT is metabolically deleterious and leg SAT is protective," they conclude.
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By Sally Robertson