Predictors of Left Ventricular Deterioration in people with and without Type 2 Diabetes: The Hoorn Study

Patients with type 2 diabetes (DM2) have increased prevalence of Left
Ventricular (LV) hypertrophy and symptomatic and asymptomatic LV dysfunction.
In cross-sectional data from the Hoorn Study the increased LV mass in DM2 could
not be explained by arterial stiffness or impaired flow mediated vasodilation,
or traditional risk factors. In contrast to increased LV mass, of which less
than 10% could be attributed to insulin and glucose levels, over 30% of the
elevated prevalence of systolic and diastolic LV dysfunction was attributable
to high levels of insulin and glucose.
This study will be the first population based prospective study with repeated
echocardiographic examinations of LV structure and function. We hypothesise
that progression of LV deterioration will be related to insulin resistance,
metabolic syndrome, arterial stiffness, endothelial dysfunction, micro-vascular
angiopathy, and low grade inflammation.

1. To study the rate of change of diastolic and systolic LV function and LV
structure, and the incidence of heart failure over a 7-year period in subjects
with and without DM2
2. To study the potential determinants of accelerated deterioration of LV
structure and function, focussing on:
- insulin resistance and/or metabolic syndrome
- micro vascular angiopathy
- arterial stiffness and endothelial dysfunction
- low grade inflammation

Cohort study.

· The subjects will have to visit the Diabetes Care and Research Centre Hoorn
(DOC) 2 time for 6 hours total. Blood samples will be taken.
· The subjects are now 58-93 years old. Considering this age range the present
project may place considerable burden on the subjects. For this reason the
measures are clustered together to ensure that the subjects have to visit the
DOC no more than 2 times and for a maximum of 4 hours per visit. All
measurements will be performed by trained research assistants to make each
visit as comfortable as possible.
· Subjects have to remain fasted at arriving for the visit. A total amount of
35 ml of blood will be withdrawn by means of vena puncture (and a capillary
blood sample of the finger). This could cause a bruise.
· During echocardiographic measurements, the subject has to lie on his/her left
side. Actual measurements will be done afterwards in digitally stored images,
to limit the amount of time to a maximum of 30 minutes.
· During each vascular measurement, the subject has to stay in a fixed,
immobilised position for a maximum of 10 min.
· When measuring blood pressure, the inflation of the cuff may cause transient
paraesthesia in the hand.
· The OGTT could cause vomiting.
· Subjects have to fill in The Hoorn Study questionnaire (developed by the EMGO
institute), the Diabetes Symptom Checklist 2, the LAPAQ, the IADL, the SF-12,
and the CES-D.
· 6 electrodes will be placed on places surrounding the heart during the
biometrical measurements for registration of heart rate variability.