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.1522

BolusShort 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)

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

BasalIntermediate 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

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

  • convenience; decreases HbA1c more than basal only

  • limited flexibility with fixed dose; not suitable if tight control desired

  • BID—twice daily, DM—diabetes mellitus, HbA1c—hemoglobin A1c, 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 HbA1c 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).