Virus could give you diabetes later in life
28 August 2012
Cytomegalovirus (CMV) infection is a significant risk factor
for type 2 diabetes in the elderly, according to research published in
the journal Immunity and Ageing.
Most people infected with CMV carry it without ill effects. Once
infected, however, you are infected for life and, although it
normally is dormant, it can become active again at any point in
Obesity, inactivity and aging are known to be associated with
insulin resistance, one of the first signs of incipient diabetes.
However only a third of those with insulin resistance go on the
develop type 2 diabetes. So what marks these people as different?
Why do their pancreas’ fail? Genetic and environmental factors are
thought to play a part but so also does inflammation. People with
type 2 diabetes usually have raised levels of biological markers for
inflammation such as elevated CRP and larger numbers of active white
Chronic infections including CMV can ‘stress’ the immune system and
when researchers from Leiden University Medical Centre and
University of Tubingen Medical School compared glucose regulation
with antibodies to CMV (or CMV seropositivity) in over 500
participants of the Leiden 85-plus Study they found that having CMV
was associated with type 2 diabetes.
The researchers suggest that CMV could be either acting directly on
pancreatic cells or indirectly by causing the immune system
attacking the pancreas. Dr Andrea Maier, who led the investigation
explained, “ In our study we realised that although CMV
seropositivity was associated with type 2 diabetes, higher levels of
HnA1c and high non-fasting glucose the actual level of antibodies
against CMV was not. ”
This study is looking at the effect of CMV on the very old. By their
very nature these people have had longer to become infected with CMV
and have low risks for other factors which are linked to diabetes or
to cardiovascular disease. While it may not be possible to
extrapolate these findings to the general population it seems likely
that finding a way to overcome CMV infections may reduce diseases,
such as diabetes, later in life.
Sijia Chen, Anton JM de Craen, Yotam Raz, Evelyna Derhovanessian,
Ann CTM Vossen, Westendorp GJ Rudi, Graham Pawelec and Andrea B
Maier. Cytomegalovirus seropositivity is associated with glucose
regulation in the oldest old. Results from the Leiden 85-plus Study.
Immunity & Ageing (in press).