Diabetes Care, Vol 21, Issue 10 1707-1713, Copyright © 1998 by American Diabetes Association
Optimal provision of daytime NPH insulin in patients using the insulin analog lispro
AB Ahmed and PD Home
Human Metabolism and Diabetes Research Centre, University of Newcastle upon Tyne, UK.
OBJECTIVE: Insulin lispro improves early postprandial blood glucose control
but can result in late interprandial hyperglycemia. As an approach to
resolving this problem, we performed a randomized, crossover study with
four treatment arms, comparing the daytime metabolic profile after either
premeal lispro alone or premeal lispro with optimal daytime NPH insulin and
with standard human regular insulin. RESEARCH DESIGN AND METHODS: Twelve
C-peptide negative type 1 diabetic patients were studied on four separate
study days, at least 7 days apart. On each study day, patients received one
of the four study insulin treatments, in random order, with identical meals
and snacks. The four treatments were 1) premeal human regular insulin
before lunch and supper at unchanged dose; 2) premeal lispro (unchanged
dose) at lunchtime and dinner; 3) pre-lunch reduced-dose lispro (70%)
before lunch and supper with supplemental lunchtime NPH and with a 6-h
interval until dinner; and 4) pre-lunch reduced-dose lispro (70%) before
lunch and supper with supplemental lunchtime NPH and with a 8-h interval
until dinner. All patients were using their usual premeal plus basal
insulin regimen during the period of the study, with human regular insulin
before meals and NPH insulin at bedtime. RESULTS: Postprandial blood
glucose concentrations (1230-1500) were lower after reduced or usual lispro
dose compared with human regular insulin (5.5+/-0.2 and 5.6+/-0.2 vs.
8.2+/-0.5 mmol/l, P < 0.001), with no difference between the lispro
doses. However, prepran-Dial (1800) blood glucose levels deteriorated to
higher levels after usual-dose lispro alone compared with either human
regular insulin (P < 0.05) or reduced-dose lispro plus NPH (P < 0.05)
(8.9+/-0.3 vs. 7.1+/-0.8 and 6.4+/-0.4 mmol/l), with no difference between
human regular insulin and reduced-dose lispro plus NPH. During the 2 h
between the usual and delayed mealtime, blood glucose concentrations
remained controlled on lispro plus NPH (2000: 6.5+/-0.4 mmol/l).
CONCLUSIONS: Reduced-dose lunchtime lispro plus NPH maintained the
improvement in postprandial blood glucose control with no deterioration in
interprandial blood glucose control, even up to a late meal.