Very little data is available on the effects of type 2 diabetes on
central artery stiffness which is a risk factor for atherosclerosis and heart
attacks.
‘Controlling elevated fasting and post-prandial blood sugar levels is vital to reduce the risk of central artery stiffness and consequently the risk of heart attack.’
The
current study
aimed to determine the
alterations in central artery stiffness in type 2 diabetes over a
5 year follow-up period. The independent influences of both fasting and
post-prandial blood sugar levels were analyzed.
The
study team believed this knowledge might give a better insight into management
of type 2 diabetes, and thereby help prevent complications.
Methods of the Study
- The participants in the study included 1680 persons 18 years or
older who took part voluntarily in a huge medical check-up program across
several centers in Beijing over two years from May 2007 to July 2009.
- The height, weight, and blood pressure of all the participants were recorded. Blood samples were
drawn to measure fasting and post-prandial blood sugar levels, serum lipid
levels and a diagnosis of type 2 diabetes and/or hyperlipidemia was made
using established clinical criteria.
- Arterial
stiffness was assessed by measuring the carotid-femoral pulse wave velocity
(cfPWV). The cfPWV was
measured by determining the time taken for the pulse to travel from the
carotid artery to the femoral artery, both during the initial as well as
the follow up visit conducted in 2013. The cut-off value for cfPWV is 12 m/sec as laid down by
international criteria.
- The follow-up visit was conducted between February and September
2013.
- For the final analysis, 898
participants were available due to loss of some participants and
exclusion of ineligible candidates.
Results of the Study
After
analyzing the data collected the following observations were made.
- The median age of volunteers was 53 (range 23-96 years) with 497
women and 401 men.
- Incidence of type 2 diabetes was 11.4% at the start of the study.
- Median cfPWV at start and follow-up was 9.8 m/sec and 10.3 m/sec
respectively, reflecting an increase in the values over time.
- The increase in cfPWV was
0.6 m/sec in participants without type 2 diabetes and 1.2 m/sec on an
average in persons with type 2 diabetes.
- Persons with high systolic
blood pressure, high fasting
and post-prandial blood sugar levels showed a higher incidence of cfPWV values greater than 12 m/sec
compared to persons with normal systolic blood pressure and normal blood
sugar measurements.
- High cfPWV (greater than 12 m/sec) was
noted to be higher in persons over 60 years, males, and those with coronary artery disease and type 2
diabetes.
The
current study indicates that persons with type 2 diabetes had significantly
higher rise in cfPWV compared to those without type 2 diabetes.
Arterial Stiffness and cfPWV
Carotid-femoral pulse wave velocity (PWV),
a measure of arterial stiffness, is the time taken for
the arterial pulse to
propagate from the carotid to
the femoral artery.
Arterial
stiffness is considered to be an important predictor of the risk of
pathological lesionsdeveloping
in the blood vessels termed
atherosclerosis
that cause narrowing of the vessels; if these lesions occur in the coronary blood
vessels, heart attack or myocardial infarction can occur.
Of the various non-invasive methods
available to assess arterial stiffness,
cfPWV
is considered the gold standard.
The
cut-off
for cfPWV laid down by earlier studies is
12 m/sec. Higher values of cfPWV are therefore likely increase risk
of atherosclerosis and heart disease.
How
Type 2 Diabetes Causes Central Artery Stiffness
Type 2 diabetes causes arterial stiffness
by several mechanisms that include the following:
- Release of pro-inflammatory
chemicals resulting in chronic inflammation of the vessel wall.
- In diabetes the endothelial cell
nitric oxide (a vessel wall relaxant) is reduced leading to an increased
stiffness of the vessel wall
- Type 2 diabetes causes structural
changes in the blood vessel wall by altering the collagen and elastin.
- In type 2 diabetes, there is
increased production of harmful reactive oxygen species that cause
inflammation and thickening of the vessel wall.
Conclusion
In
conclusion, the current study
establishes
that both fasting and post-prandial blood sugar levels contribute to the
development of arterial stiffness. Therefore physicians must be diligent in
controlling both elevated fasting as well as post-prandial blood glucose to
reduce incidence of atherosclerosis and heart disease in type 2 diabetes.
References :- Evaluation of Carotid-Femoral Pulse Wave Velocity - (http://hyper.ahajournals.org/content/45/2/222)
- Reactive oxygen species as mediators of angiogenesis signaling: role of NAD(P)H oxidase. - (https://www.ncbi.nlm.nih.gov/pubmed/15544038)
Source: Medindia