Diabetes Care, Vol 21, Issue 10 1596-1602, Copyright © 1998 by American Diabetes Association
The Veterans Affairs Implantable Insulin Pump Study: effect on cardiovascular risk factors
WC Duckworth, CD Saudek, A Giobbie-Hurder, WG Henderson, RR Henry, DE Kelley, SV Edelman, FJ Zieve, RA Adler, JW Anderson, RJ Anderson, BP Hamilton, TW Donner, MS Kirkman and NA Morgan
Omaha Veterans Affairs Medical Center, Nebraska, USA. wduckwor@unmc.edu
OBJECTIVE: To determine whether implantable insulin pump (IIP) and
multiple-dose insulin (MDI) therapy have different effects on
cardiovascular risk factors in insulin-requiring patients with type 2
diabetes. RESEARCH DESIGN AND METHODS: A randomized clinical trial was
conducted at seven Veterans Affairs medical centers in 121 male patients
with type 2 diabetes between the ages of 40 and 69 years receiving at least
one injection of insulin per day and with HbA1c, levels of > or =8% at
baseline. Weights, blood pressures, insulin use, and glucose monitoring
data were obtained at each visit. Lipid levels were obtained at 0, 4, 8,
and 12 months, and free and total insulin levels were obtained at 0, 6, and
12 months. All medications being taken were recorded at each visit.
RESULTS: No difference in absolute blood pressure, neither systolic nor
diastolic, was seen between patients receiving MDI or IIP therapy, but
significantly more MDI patients required anti-hypertensive medications.
When blood pressure was modeled against weight and time, IIP therapy was
significantly better than MDI therapy for systolic blood pressure in
patients with BMI <33 and for diastolic blood pressure in patients with
BMI >34 kg/m2. Total cholesterol levels decreased in the overall sample,
but IIP patients exhibited significantly higher levels than MDI patients.
Triglyceride levels increased over time for both groups, with IIP patients
having significantly higher levels than patients in the MDI group. BMI was
a significant predictor of, and inversely proportional to, HDL cholesterol
level. No difference in lipid-lowering drug therapy was seen between the
two groups. Free insulin and insulin antibodies tended to decrease in the
IIP group as compared with the MDI group. C-peptide levels decreased in
both groups. CONCLUSIONS: IIP therapy in insulin-requiring patients with
type 2 diabetes has advantages over MDI therapy in decreasing the
requirement for antihypertensive therapy and for decreasing total and free
insulin and insulin antibodies. Both therapies reduce total cholesterol and
C-peptide levels.