What is the role of between meal snacks with intensive basal bolus regimens using preprandial lispro?

Hypoglycaemia avoidance for patients on intensive insulin regimens requires the eating of snacks between meals. Insulin lispro with its shorter action profile may permit omitting such snacks.

Ten Type 1 diabetes mellitus (DM) patients were rendered euglycaemic with a morning intravenous insulin infusion. Each was studied on six afternoons in random order, with previously determined equal doses of Humulin S (HS) injected at -30min, or lispro injected at 0 min before a standard lunch. The snack was either eaten mid-afternoon, combined with the lunch or omitted altogether.

Lispro and lunch with a snack combined at 0 min gave equal control to HS at -30 min and lunch at 0 min with a mid-afternoon snack. Lispro and lunch at 0 min with a mid-afternoon snack gave a lower early postprandial glucose. At 120 min glucose (mean mmol/l +/- SEM) were 7.4+/-0.8 vs. 7.0+/-1.0 (P = 1.0) and 3.9+/-0.5 (P = 0.045), respectively. The area under the insulin curve over the whole afternoon was similar for HS and lispro (13193.3+/-974.6 vs. 13193.6+/-809.9 mIU/min, P = 1.0) but with a greater peak for lispro than HS with lispro falling more rapidly. Despite significantly lower lispro levels after 180 min, intermediary metabolites concentrations were similar in all HS and lispro study days.

Lispro injected immediately before combined snack and lunch and with no subsequent snack achieves equivalent control to conventional regimens using HS -30 min before lunch and mid-afternoon snack. Lispro taken with traditional meal patterns without dose reduction risks early postprandial hypoglycaemia and late hyperglycaemia.