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PARIS, June 17 -- A herpes virus is associated with an atypical form of type 2 diabetes found in people of African origin, researchers said here.

Ketosis-prone type 2 diabetes mellitus, first observed in the late 1960s, is an acute-onset form of the disease that requires insulin treatment and is followed by long periods of remission, according to Jean-François Gautier, M.D., Ph.D., of the Saint-Louis University Hospital here, and colleagues.

In a cross-sectional, case-control study, patients with the illness were nearly 40 times more likely to have antibodies to human herpesvirus-8 (HHV-8) than were those with non-ketotic diabetes, Dr. Gautier and colleagues said in the June 18 issue of the Journal of the American Medical Association.

Those patients were also more than 10 times more likely to show evidence of the virus than non-diabetic controls, the researchers said.

Ketosis-prone diabetes has become one of the most frequent forms of the disease among people of African origin, the researchers said, and between 30% and 60% of adults in sub-Saharan Africa have markers of HHV-8 infection.

Those two facts suggested that the virus might play a role in the onset of the disease, the researchers said. "We hypothesized that ketosis-prone (diabetes) may be associated with a viral infection, which may also be the acute and reversible precipitating phenomenon," they said.

To test the hypothesis, they studied 187 consecutive diabetic patients seeking treatment at the Saint-Louis University Hospital. Of those, 81 had ketosis-prone and 106 had non-ketotic diabetes. The study also included 90 non-diabetic participants (from Paris and from Dakar, Senegal) matched for age and sex with the patients.

All the participants were black and of African origin, the researchers said.

Analysis showed:

• 87.7% of the patients with ketosis-prone diabetes (71 of the 81) were seropositive for HHV-8, compared with 15.1% of those with non-ketotic diabetes (16 of 106).
• Prevalence in the control group was 40% overall, with a prevalence of 39% in the French patients (16 of 41 participants) and 40.8% in those from Senegal (20 of 49).
• In comparison with the controls, the odds ratio for HHV-8 infection among those with ketosis-prone diabetes was 10.65, with a 95% confidence interval from 4.86 to 23.35, which was significant at P<0.001.
• When the non-ketotic diabetics were compared with controls, the odds ratio for HHV-8 was 0.27, with a 95% confidence interval from 0.14 to 0.53, which was significant at P<0.001.
• Finally, when both groups of diabetics were compared, the odds ratio for HHV-8 was 39.94, with a 95% confidence interval from 17.08 to 93.36, which was significant at P<0.001.

At the acute onset of the disease, the researchers also tested for HHV-8 in genomic DNA in 22 patients, 13 of them with the ketosis-prone form. The virus was found in six of those with the ketotic form, but in none of the others.

The lower incidence of HHV-8 among the non-ketotic diabetics, compared with controls, may simply be a chance effect, given the small size of the study, Dr. Gautier and colleagues said.

On the other hand, the finding might actually support the idea that ketosis-prone diabetes is an acute-onset disease caused by an environmental factor such as HHV-8.

People predisposed to type 2 diabetes -- if infected with HHV-8 before the onset of the disease -- would develop the ketosis-prone form, but if they weren't infected, would develop the classic form, the researchers argued.

They noted that their study is preliminary and is limited by a small sample size, especially regarding the number of participants tested for viral DNA. They also noted that "we have not been able to establish a temporal relationship between the virus and ketosis prone DM-2 phenotype.

The study was supported by the Assistance Publique-Hôpitaux de Paris, INSERM, the Association Française des Diabétiques, the Association de Langue Française pour l'Etude du Diabète et des Maladies Métaboliques. The researchers reported no conflicts of interest.

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