Major Finding: Average ADMA levels were 0.9 micromol/L in 40 recently diagnosed diabetic patients who were free of diabetes-related complications and medications. The value was significantly higher than the 0.7-micromol/L average level seen in 40 healthy controls
Data Source: A case-control study of patients with early type 2 diabetes and healthy controls matched for age, sex, and body mass index.
Disclosures: The investigators noted that they had no relevant disclosures.
Asymmetric dimethylarginine, or ADMA, is independently associated with diabetes, and may play a role in the development of insulin resistance, according to a study by Iranian researchers.
ADMA levels in the study were significantly higher in 40 recently diagnosed diabetic patients who were free of diabetes medications and diabetes-related complications (0.9 micromol/L), compared with 40 healthy controls matched with the patients for age, sex, and body mass index (0.7 micromol/L), reported Dr. Manouchehr Nakhjavani and colleagues at Tehran (Iran) University of Medical Sciences.
The investigators set out to evaluate the association between ADMA, a potent endogenous nitric oxide (NO) synthase inhibitor; high-sensitivity C-reactive protein (hs-CRP), a marker of chronic inflammation; and insulin resistance in patients with earlystage type 2 diabetes. Like ADMA, hs-CRP was significantly higher in the diabetes patients (3.0 mg/L) than in the controls (1.3 mg/L). Age- and sex-adjusted ADMA values were significantly correlated with the hs-CRP levels; a similar finding was reported in an earlier study, which suggested that a “complex interrelation … could exist between ADMA and chronic inflammation in the prediabetic and diabetic state,” they noted (Ann. Endocrinol. 2010 April 30 [doi:10.1016/j.ando.2010.02.026]).
The adjusted ADMA levels in the current study also were significantly correlated with homeostasis model assessment of insulin resistance (HOMA-IR) in patients, but not in controls; the association with HOMA-IR in patients remained significant after the researchers controlled for body mass index, waist circumference, serum lipids, and hs-CRP, they reported.
The finding of an association between ADMA and insulin resistance independent of hs-CRP, body adiposity, and lipid profile, “possibly shows that high ADMA in early diabetes can lead to NO depletion or ineffectiveness of NO-mediated vasodilator mechanisms associated with the progression of insulin resistance to type 2 diabetes,” the investigators wrote.
Additional studies to investigate this possibility, as well as to evaluate the association between ADMA and HOMA-IR in healthy individuals, are needed, the researchers concluded, noting that the lack of a finding of such an association in the current study conflicts with some prior studies.