Table 2

Advantages and disadvantages of insulin: Evidence for insulin analogues is limited to small, short-term trials, and benefits are modest; anecdotal experience is favourable. Recent systematic and economic reviews rigorously assessed benefits, risks, and incremental cost.15–22

INSULIN		ADVANTAGES	DISADVANTAGES
Bolus	Short acting Human regular (Humulin R, Novolin ge Toronto)	more long-term and safety data low cost extensive safety data in pregnancy	injecting 20–30 min before meals is often impractical (short acting but not rapid acting)
Bolus	Rapid acting^* Lispro (Humalog) Aspart (NovoRapid) Glulisine (Apidra)^†	inject-and-eat convenience (take just before or within 20 min of starting meals); valuable when diet or activities are unpredictable (eg, adolescents) some patients might have less hypoglycemia high patient satisfaction in type 1 DM safe during pregnancy but less experience	moderately expensive relative to clinical benefits in type 2 DM^‡
Basal	Intermediate acting Human NPH Humulin N, Novolin ge NPH	long-term safety and outcome evidence low cost convenient: might avoid need for lunchtime bolus injection (eg, good for children)	NPH vial must be mixed before withdrawing dose; affects absorption intermediate action and peak at 4–12 h predispose to hypoglycemia
Basal	Long acting Detemir (Levemir) Glargine (Lantus)	decreases nocturnal hypoglycemia (subjective, not blinded): type 2 DM estimated NNT ≥ 6 for 6–12 mo^§ slightly less weight gain vs NPH: in type 2 DM, only detemir had decrease in weight^\|\| once-daily dosing (detemir: many will require BID)	expensive relative to benefit in type 2 DM^‡ limited and inconsistent evidence for any difference in severe hypoglycemia more injections if not mixed with bolus caution needed in pregnancy
Mixed	Premixed20,21	convenience; decreases HbA_1c more than basal only	limited flexibility with fixed dose; not suitable if tight control desired

BID—twice daily, DM—diabetes mellitus, HbA_1c—hemoglobin A_1c, NNT—number needed to treat, NPH— neutral protamine Hagedorn.
↵*Rapid onset might lead to better postprandial control; significance is uncertain.
↵^†Glulisine appears similar to lispro and aspart but is too new to be included in systematic reviews referenced here.
↵^‡There are no clinically significant differences in HbA_1c control likely to affect clinical outcomes.
↵^§Most pronounced decreased risk for long-acting insulin analogs is on nocturnal hypoglycemia16 (long acting vs NPH, NNT ≥ 6 [95% confidence interval 4–33]).15
↵^||Weight change with long-acting insulin analogs vs NPH: type 1 DM −0.73 to −0.4 kg; type 2 DM −1.27 to −0.8 kg (with detemir; glargine no difference). There are questions about the clinical significance of the minor weight change of < 1.3 kg here (or < 5% in general).