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Type 2 Diabetes Mellitus Role of Insulin Gayotri Goswami, MD, FACE Assistant Clinical Professor of Medicine Division of Endocrinology & Metabolism November 9, 2009 Stages of Type 2 Diabetes Related to Beta-Cell Function 100 75 BetaCell Function 50 (%) Type 2 Phase 1 IGT 25 Postprandial Hyperglycemia 0 12 10 6 2 Type 2 Phase 3 Type 2 Phase 2 0 2 6 Years from Diagnosis Adapted from Lebovitz HE. Diabetes Reviews. 1999;7(3). 10 14 Contributions of FPG and PPG to Overall Glycemia in T2DM Contribution (%) PPG + FPG = A1C (%) PPG FPG 80 70 60 50 40 30 20 10 0 1 <7.3 2 7.3- 8.4 3 4 8.5 - 9.2 9.3- 10.2 A1C Quintiles 5 >10.2 FPG = fasting plasma glucose. PPG: Post prandial glucose Adapted with permission from Monnier L et al. Diabetes Care. 2003;26:881-885. Targets for Glycemic Control* Normal Goal <6.0 <110 <7.0 70-130 <180 <6.0 <110 <6.5 <110 <135 <6.0 <110 <6.5 <110 <140 American Diabetes Association1 A1C (%) Preprandial plasma glucose (mg/dL) Peak postprandial plasma glucose (mg/dL) European Diabetes Policy Group2 A1C (%) Preprandial plasma glucose (mg/dL) Postprandial glucose (mg/dL) American Association of Clinical Endocrinologists3 A1C (%) Preprandial plasma glucose (mg/dL) Postprandial glucose (mg/dL) *More stringent goal of <6.0% should be considered for individual patients. Generally, A1C goal for each patient is an A1C as close to normal as possible without significant hypoglycemia. A1C = glycosylated hemoglobin A1C. 7 1. ADA. Diabetes Care. 2006;29(suppl 1):S4-S42. 2. European Diabetes Policy Group 1999. Diabet Med. 1999;16:716-730. 3. Feld S. Endocr Pract. 2002;8(suppl 1):40-82. “Although insulin therapy has not traditionally been implemented early in the course of Type 2 diabetes, there is no reason why it should not be…” Nathan DM. NEJM. Oct 24, 2002;347(17):1342-1349. Metabolic Management of type 2 DM Nathan et al, A Consensus Statement from the American Diabetes Association and the European Association for the Study of Diabetes. Diabetes Care,29:759-764,2006 Insulin • Insulin is composed of 2 polypeptide chains the A and B linked together by disulphide bonds • Among most species the A chain consists of 21 AA and the B of 30 AA • Although the AA sequences differ in species there are certain segments of the molecule that are highly conserved Insulin • Most affective agent, when used in adequate doses to decrease any level of A1c to therapeutic goal • Relatively large doses are used in Type 2 insulin resistant patients when compared to Type 1 • Has beneficial effects on TG and HDL but can cause weight gain • Important side effect is hypoglycemia (can be reduced by education, peakless and short acting insulins) Ideal insulin therapy • One which replicates physiologic insulin secretion • Maintains near-normal glycemia • Minimizes long term complications • Improves quality of life Physiologic Blood Insulin Secretion Profile 75 Breakfast Lunch Dinner 50 Plasma Insulin (µU/mL) 25 4:00 8:00 12:00 16:00 20:00 Time Adapted from White JR, Campbell RK, Hirsch I. Postgraduate Medicine. June 2003;113(6):30-36. 24:00 4:00 8:00 Ideal Basal/Bolus Insulin – elementary principal 75 Breakfast Lunch Dinner Glucose Bolus Insulin Base Insulin Plasma Insulin 50 (U/mL) 25 0 4:00 8:00 12:00 16:00 20:00 24:00 4:00 8:00 Time Skyler J, Kelley’s Textbook of Internal Medicine 2000. Loss of Early Insulin Release Leads to Postprandial Hyperglycemia Plasma Insulin Plasma Glucose 60 360 270 40 (mg/dL) (mU/L) 180 20 90 0 –1 0 1 2 3 4 5 –1 Hours After Glucose Ingestion Healthy Subjects Patients With Type 2 Diabetes Mitrakou A, et al. Diabetes. 1990;39:1381–1390. 0 1 2 3 4 5 Components of a daily regimen • Basal: maintains interprandial and overnight glycemic control • Bolus /Nutritional/Prandial: controls the post meal glucose surge What are insulin analogs? • An insulin analog is an altered form of insulin. • Through genetic engineering of the underlying DNA,the amino acid sequence of insulin is changed to alter its absorption, distribution, metabolism and excretion. INSULINS • • • Peak (duration) hrs RAPID-ACTING INSULIN ANALOGS – Humalog (lispro) – Novolog (aspart) – Glulisine (epidra) SHORT-ACTING - Regular 1-2 1-2 1-2 2-4 (3-6) INTERMEDIATE-ACTING – NPH (Neutral Protamine Hegedron) • (2-6) (2-6) (2-6) LONG ACTING – Lantus / glargine – Levemir / detemir 6-12 none (10-24) - (10-24) Fixed dose insulin mixes HUMULIN (NPH/REG) –70/30 –50/50 HUMALOG (Prot-lispro/free lispro) –75/25 NOVOLIN (NPH/REG) –70/30 NOVOLOG MIX (Prot-aspart/aspart) –70/30 Insulin delivery devices Long Acting Analogs Lantus (Glargine)- formulary • Two positively charged arginine molecules are added to the C-terminus of the B-chain, asparagine at position 21 in the A-chain is replaced by glycine Lantus • Upon injection into the subcutaneous space(pH 7.4), the acidic (4.0) glargine solution is neutralized and it forms an amorphous suspension • resulting in delayed absorption and an extended duration of action. • Reduced incidence of hypoglycemia compared with NPH Levemir (Detemir) . • To the Lysine AA at position B29 a fatty acid (myristic acid ) is bound. • After it is absorbed it binds to albumin through the fatty acid at position B29 and the slowly dissociates from this complex. NPH- formulary • Neutral Protamine Hegedron: is a suspension of crystalline zinc insulin combined with a polypeptide protamine • Intermediate acting and the most commonly used basal insulin • Half life is 8 hours and reaches a peak concentration at 4-6 hrs Short Acting Analogs Lispro (Humalog)- formulary • Lysine and proline residues on the C-terminal end of the B-chain are reversed Insulin Glulisine (Apidra) •The AA asparagine at position B3 is replaced by lysine and the lysine in position B29 is replaced by glutamic acid Aspart (Novolog) • The AA , B28, which is normally proline , is substituted with an aspartic acid residue Human Insulin Time-Action Patterns Change in serum insulin Normal insulin secretion at mealtime Theoretical representation of expected insulin release in nondiabetic subjects Baseline Level Time (hours) SC injection Human Insulin Time-Action Patterns Change in serum insulin Normal insulin secretion at mealtime Regular insulin (human) Theoretical representation of profile associated with Regular Insulin (human) Baseline Level Time (hours) SC injection Analog Insulin Time-Action Patterns Change in serum insulin Normal insulin secretion at mealtime Theoretical representation of expected insulin release in nondiabetic subjects Baseline Level Time (hours) SC injection Analog Insulin Time-Action Patterns Change in serum insulin Normal insulin secretion at mealtime Rapid-Acting Insulin Analog Theoretical representation of profile associated with rapid-acting Insulin Analog Baseline Level Time (hours) SC injection Analog Insulin Time-Action Patterns Change in serum insulin Normal insulin secretion at mealtime QD (basal) Analog Insulin Theoretical representation of profile associated with Basal Analog Insulin Baseline Level Time (hours) SC injection Human Insulin Time-Action Patterns Change in serum insulin Normal insulin secretion at mealtime Human Premix 70/30 (70% NPH & 30% Regular) Theoretical representation of profile associated with Human Premix 70/30 Baseline Level Time (hours) SC injection Analog Insulin Time-Action Patterns Change in serum insulin Normal insulin secretion at mealtime Insulin Analog Premix Theoretical representation of profile associated with Insulin Analog Premix Baseline Level Time (hours) SC injection Advantages of rapid acting insulin analogs • Restores the early insulin peak in combination with meal ingestion • Prevents the hyperinsulinemia resulting from the late absorption of regular insulin and thereby protects against hypoglycemia OPTIONS……… • • Once daily background or basal insulin if fasting BG is elevated but glucose values remain stable during the day A simple and practical approach is to implement once daily basal insulin and continue OAD therapy, titrating according to FBG * •INSIGHT(Implementing New Strategies with Insulin Glargine for Hyperglycemic Treatment – Gerstein et al 2006.Diab.Med.23:736-742 OPTIONS……… • Once daily or twice daily pre-mixed insulin analogue, orally administered drugs may or may not be continued • Basal bolus therapy…..first initiate basal along with 1 bolus injection before the largest meal and eventually at each meal if needed OAD and Insulin • Proven to be effective in a review of 20 RCT • Provides comparable glycemic control to insulin monotherapy • Reduction in total daily insulin requirements • Reduces weight gain and helps glycemic control by peripheral insulin sensitization and inhibiting hepatic gluconeogenesis Dosing • Glargine is effectively administered either in the morning or evening, provided the timing of injection is consistent each day • Detemir is administered both once and twice daily • NPH is usually administered twice daily, in the morning and at bedtime Dosing • Short acting analogs are given 5-15 minutes before a meal while Apidra or Glulysine can be given upti 20 minutes after start of a meal • RI is given atleast 20-30 minutes before a meal • A short acting analog can be started as 10% of the TDD (basal insulin can then be decreased by 10%) and can be added to the heaviest meal What doses to start with…….. • • • • • With HbA1c <8%, begin 0.1U/Kg body weight HbA1c 8-10%, start 0.2U/kg body weight HbA1c >10%, start 0.3U/Kg body weight 10 units /day With pre-mixes can divide the total dose by 2 if used twice a day • With insulin glargine, adjust dose every 3-7 days until target fasting dose is reached Bergenstal Endocrine Practice,Jan 2006 Titration • Forced weekly titration (physician led) Treat to Target Trial (Glargine/NPH) & (Detemir BID/NPH) • Patient- led titration (usually every 2-3 days according to BG goal) AT.LANTUS trial PREDICTIVE trial Titration • For titrating prandial insulin pre-meal BG and 2 hour post meal BG is needed and doses are adjusted according to the goals Glycemic Control LANTUS Vs NPH + Oral agents (Treat to Target Trial) Large multicenter trial, patients had A1c Between 8-10%, 24 weeks duration with either Lantus/NPH + 2 oral agents to bring FBG to <100mg/dL Riddle et al.Diabetes Care;2003:3080-3086 Adverse effects 4T Study (Three year efficacy of complex insulin regimens ) • • • • • 1. 2. 3. 3 year open label, multicenter trial 708 patients with A1c levels between 7-10% On Metformin and a SFU Outcomes – A1c , hypoglycemia & weight gain Randomly assigned to 3 groups Biphasic aspart Aspart pre-meals TID Basal Detemir once daily (twice if needed) Holman et al.NEJM.2009,361,18 Results • Median A1c was similar in biphasic (7.1%) prandial (6.8%) and basal (6.95) • Median rates of hypoglycemia per patient per year were lowest in the basal (1.7), biphasic (3.0), and prandial (5.7), p<0.001 for overall comparison • Mean weight gain was higher in the prandial group(5.7kg±0.5) than either biphasic (6.4±0.5) or basal (3.6 ±0.5) Adverse effects • Detemir has been associated with less weight gain when compared with NPH at equivalent glycemic control • Detemir also had significantly less weight gain when compared with glargine (Detemir 3kg; glargine 3.9kg,P<0.012) Raslova et al, 2004.Diabetes.Res.Clin.Pract 66:193-20 Haak T et al.2005.Diabetes Obes metab.7:56-64 Hermansen K et al 2006.Diabetes Care 29;1269-1274 Conclusions • The insulin analogues offer improved pharmacokinetic and pharmacodynamic profiles compared to NPH and RI and therefore offer advantages with respect to safety,efficacy and variability • These advantages may help Type 2 Diabetics overcome some of the barriers associated with insulin initiation, hypoglycemia and weight gain Conclusions • Lantus offers a consistent 24 hour profile and predictability and a lower risk of hypoglycemia when compared with NPH and therefore facilitates more aggressive titration • Detemir is associated with equivalent glycemic control, less risk of hypoglycemia lower withinsubject day-to-day control and less weight gain Questions ????