OBJECTIVETo compare the pharmacokinetics and pharmacodynamics of NPH, glargine, and detemir insulins in type 2 diabetic subjects.RESEARCH DESIGN AND METHODSThis study used a single-blind, three-way, cross-over design. A total of 18 type 2 diabetic subjects underwent a euglycemic clamp for 32 h after a subcutaneous injection of 0.4 units/kg at 2200 h of either NPH, glargine, or detemir after 1 week of bedtime treatment with each insulin.RESULTSThe glucose infusion rate area under the curve0–32 h was greater for glargine than for detemir and NPH (1,538 ± 688; 1,081 ± 785; and 1,170 ± 703 mg/kg, respectively; P < 0.05). Glargine suppressed endogenous glucose production more than detemir (P < 0.05) and similarly to NPH (P = 0.16). Glucagon, C-peptide, free fatty acids, and β-hydroxy-butyrate were more suppressed with glargine than detemir. All 18 subjects completed the glargine study, but two subjects on NPH and three on detemir interrupted the study because of plasma glucose >150 mg/dL.CONCLUSIONSCompared with NPH and detemir, glargine provided greater metabolic activity and superior glucose control for up to 32 h.

OBJECTIVE This study characterized the pharmacokinetics (PK), pharmacodynamics (PD), and endogenous (hepatic) glucose production (EGP) of clinical doses of glargine U300 (Gla-300) and glargine U100 (Gla-100) under steady-state (SS) conditions in type 1 diabetes mellitus (T1DM). RESEARCH DESIGN AND METHODS T1DM subjects (N = 18, age 40 ± 12 years, T1DM duration 26 ± 12 years, BMI 23.4 ± 2 kg/m2, A1C 7.19 ± 0.52% [55 ± 5.7 mmol · mol−1−1]) were studied after 3 months of Gla-300 or Gla-100 (evening dosing) titrated to fasting euglycemia (random, crossover) with the euglycemic clamp using individualized doses (Gla-300 0.35 ± 0.08, Gla-100 0.28 ± 0.07 units · kg−1). RESULTS Plasma free insulin concentrations (free immunoreactive insulin area under the curve) were equivalent over 24 h with Gla-300 versus Gla-100 (point estimate 1.11 [90% CI 1.03; 1.20]) but were reduced in the first 6 h (0.91 [90% CI 0.86; 0.97]) and higher in the last 12 h postdosing (1.38 [90% CI 1.21; 1.56]). Gla-300 and Gla-100 both maintained 24 h euglycemia (0.99 [90% CI 0.98; 1.0]). The glucose infusion rate was equivalent over 24 h (1.03 [90% CI 0.88; 1.21]) but was lower in first (0.77 [90% CI 0.62; 0.95]) and higher (1.53 [90% CI 1.23; 1.92]) in the second 12 h with Gla-300 versus Gla-100. EGP was less suppressed during 0–6 h but more during 18–24 h with Gla-300. PK and PD within-day variability (fluctuation) was 50% and 17% lower with Gla-300. CONCLUSIONS Individualized, clinical doses of Gla-300 and Gla-100 resulted in a similar euglycemic potential under SS conditions. However, Gla-300 exhibited a more stable profile, with lower variability and more physiological modulation of EGP compared with Gla-100.

OBJECTIVETo investigate concentration of plasma insulin glargine after its subcutaneous dosing compared with concentration of its metabolites 1 (M1) and 2 (M2) in subjects with type 2 diabetes.RESEARCH DESIGN AND METHODSNine subjects underwent a 32-h euglycemic glucose clamp study (0.4 units/kg glargine after 1 week of daily glargine administration). Glargine, M1, and M2 were measured by a specific liquid chromatography-tandem mass spectrometry assay.RESULTSGlargine was detected in only five of the nine subjects, at few time points, and at negligible concentrations. M1 was detected in all subjects and exhibited the same pattern as traditional radioimmunoassay-measured plasma insulin. M2 was not detected at all.CONCLUSIONSAfter subcutaneous injection, glargine was minimally detectable in blood, whereas its metabolite M1 accounted for most (>90%) of the plasma insulin concentration and metabolic action of the injected glargine.

OBJECTIVETo compare pharmacokinetics (PK) and pharmacodynamics (PD) of insulin glargine in type 2 diabetes mellitus (T2DM) after evening versus morning administration. RESEARCH DESIGN AND METHODSTen T2DM insulin-treated persons were studied during 24-h euglycemic glucose clamp, after glargine injection (0.4 units/kg s.c.), either in the evening (2200 h) or the morning (1000 h). RESULTSThe 24-h glucose infusion rate area under the curve (AUC 0-24h ) was similar in the evening and morning studies (1,058 6 571 and 995 6 691 mg/kg 3 24 h, P = 0.503), but the first 12 h (AUC 0-12h ) was lower with evening versus morning glargine (357 6 244 vs. 593 6 374 mg/kg 3 12 h, P = 0.004), whereas the opposite occurred for the second 12 h (AUC 12-24h 700 6 396 vs. 403 6 343 mg/kg 3 24 h, P = 0.002). The glucose infusion rate differences were totally accounted for by different rates of endogenous glucose production, not utilization. Plasma insulin and C-peptide levels did not differ in evening versus morning studies. Plasma glucagon levels (AUC 0-24h 1,533 6 656 vs. 1,120 6 344 ng/L/h, P = 0.027) and lipolysis (free fatty acid AUC 0-24h 7.5 6 1.6 vs. 8.9 6 1.9 mmol/L/h, P = 0.005; b-OH-butyrate AUC 0-24h 6.8 6 4.7 vs. 17.0 6 11.9 mmol/L/h, P = 0.005; glycerol, P < 0.020) were overall more suppressed after evening versus morning glargine administration. CONCLUSIONSThe PD of insulin glargine differs depending on time of administration. With morning administration insulin activity is greater in the first 0-12 h, while with evening administration the activity is greater in the 12-24 h period following dosing. However, glargine PK and plasma C-peptide levels were similar, as well as glargine PD when analyzed by 24-h clock time independent of the time of administration. Thus, the results reflect the impact of circadian changes in insulin sensitivity in T2DM (lower in the night-early morning vs. afternoon hours) rather than glargine per se.

OBJECTIVECrystalline NPH insulin comes in a two-phase solution with either a solvent or a rapid-acting insulin (in premixed formulations) and needs adequate mixing for complete resuspension before injection. The aim of this study was to establish pharmacokinetics (PK) and pharmacodynamics (PD) after injection of appropriately resuspended versus nonresuspended NPH insulin. RESEARCH DESIGN AND METHODSPK and PD were assessed after subcutaneous injection of NPH insulin 0.35 units/kg at steady state by pen either resuspended (R+, tipping of insulin pen 20 times) or nonresuspended (pen maintained in fixed position either horizontally [R-horizontal] or vertically with tip up [R-up] or tip down [R-down]). Eleven subjects with type 1 diabetes (age 31.5 6 12 years, diabetes duration 17.5 6 7.7 years, BMI 22.9 6 1.5 kg/m 2 , A1C 7.2 6 0.4% [55.2 6 4.4 mmol/mol]) were studied (euglycemic clamp) with a randomized crossover design. RESULTSCompared with resuspended NPH insulin (R+), nonresuspended NPH insulin resulted in profound PK/PD differences with either reduced (R-horizontal and R-up) or increased (R-down) plasma insulin concentrations [FIRI_AUC (0-end of study) (free immunoreactive insulin area under the concentration-time curve between 0 and end of study)] and PD activity [glucose infusion rate (GIR)_AUC (0-end of study) ] (all P < 0.05). Duration of NPH insulin action was shorter in R-up (9.4 6 1.7 h) but longer in R-down (15.4 6 2.3 h) compared with R+ (11.8 6 2.6 h) (P < 0.05). Within-subject variability (percent coefficient of variation) among studies was as high as 23% for PK [FIRI_AUC (0-end of study) ] and 62% for PD [GIR_AUC (0-end of study) ]. CONCLUSIONSCompared with resuspended NPH insulin, lack of resuspension profoundly alters PK/PD and may importantly contribute to day-to-day glycemic variability of type 1 diabetes.