TARGETS OF GLYCEMIC CONTROL IN PATIENTS WITH DIABETES

Transcription

1 04 TARGETS OF GLYCEMIC CONTROL IN PATIENTS WITH DIABETES 4. 1 TARGETS OF GLYCEMIA According to widely accepted suggestions targets of glycemic control for adults and pregnant women with diabetes are summarized in Table 4.1. Table 4.1 Targets of glycemic control Ideal Target In pregnancy A1C <6% 6.5% (*) 6.5% (preferably <6%) FPG and mg/dl preprandial PG mg/dl mg/dl (*) 1 h postprandial PG <120 mg/dl - <140 mg/dl (**) (preferably <120 mg/dl) 2 h postprandial PG <130 <140 <120 mg/dl mg/dl mg/dl (*) (*) The most recent glycemic goals recommended by the American Diabetes Association (ADA) are A1C level of <7%, preprandial PG mg/dl and postprandial peak level of PG <180 mg/dl (postprandial peak is minutes after a meal), and to measure postprandial blood glucose levels when A1C do not reach the target despite preprandial PG levels are in the target ranges. (**) 1 h postprandial blood glucose levels should be monitored in pregnant women with diabetes. ADA Clinical Practice Recommendations. Standards of medical care. Diabetes Care 2009;32 (Suppl.1): S Nathan DM, et al. Management of hyperglycemia in type 2 diabetes: A consensus statement from the DA and EASD. Diabetes Care 2006;29: AACE/ACE. Endocrine Practice. 2002;8(Suppl. 1):40-82 IDF Global Guideline for Type 2 Diabetes, Targets of Glycemic Control in Different age Groups In children and adolescents Targets of glycemic control in prepubertal children should be determined by a pediatric endocrinologist to minimize the risk of hypoglycemia (especially at night). ADA recommendations on this issue are summarized below; In preschool children (younger than 6 years of age) target fasting/preprandial and bedtime/late night PG concentrations are and mg/dl, respectively, and A1C concentration should be % In school-age children (8-12 years of age) recommended fasting/preprandial and bedtime/late night target PG concentrations are and mg/dl, respectively, A1C concentration should be less than 8%. 18

2 Turk JEM 2010; 14: Suppl Targets of Glycemic Control in Patients with Diabetes 19 In adolescents (13-18 years of age) glycemic goals should be close to the targets of adults. Accordingly, fasting/preprandial and bedtime/late night target PG concentrations of and mg/dl, and postprandial 2 h PG concentration of <150 mg/dl are recommended; target A1C is %. In elderly patients and those with short life expectancy Generally strict metabolic control is not recommended in elderly patients with diabetes and in patients with short life expectancy or those who have severe/advanced comorbidities. The results of ACCORD and VA-DT studies, reported in 2007 and 2008, have shown that strict metabolic control may be associated with increased CVD in elderly patients with diabetes for more than 10 years. Hypoglycemia is associated with increased risk of mortality. To determine the targets of glycemic control individually, life expectancy should be considered beyond the patient s chronological age; life expectancy >15 years without any major comorbidity; A1C 6.5% life expectancy between 5-15 years with moderate comorbidity; A1C 7.5% life expectancy <5 years with any major comorbidity; A1C 8.5%. In women with diabetes planning for pregnancy Preconception A1C threshold for women with diabetes should not exceed 2 standard deviations above the upper limit of nondiabetic range ( 6.5%), preferably it should be 6.0% in well-motivated patients Measurement and Evaluation of Haemoglobin A1C The HbA1c (A1C) level reflects the average blood glucose concentration over the previous three months. A1C test does not require fasting. The normal range of A1C by high performance liquid chromatography (HPLC) assay as used in DCCT is %. In this study the upper limit of the non-diabetic A1C range is 6.0% (mean 5.9% + 2 standard deviation). Table 4.2 shows estimated average glucose levels corresponding to A1C values measured by standard method used in DCCT and to The A1C-derived average glucose (ADAG) study. ADAG average glucose levels can be calculated by the following formula; Average glucose =28.7xA1C 46.7 Glucose levels can be calculated from the related website ( Table 4.2 The relationship between A1C and average glycemia A1C (%) DCCT average ADAG average glucose (mg/dl) glucose (*) (mg/dl) (*) ADAG; A1C-derived average glucose. Average glucose = 28.7 X A1C-46.7 Nathan DM, Kuenen J, Borg R, et al. Diabetes Care 2008;31: Generally 50% of an A1C result represents the previous month's glycemia, and about 30% represents the levels over the preceding 2 nd month whereas the remaining 20% represents 3 rd month glycemia, respectively. The contribution of fasting glycemia increases with the higher levels of A1C. On the other hand, contribution of postprandial glycemia is prominent when A1C value is close to normal. The studies conducted in patients with type 1 and type 2 diabetes have shown that the risk of development of microvascular complications is closely related to the level of glycemic control (Table 4.3). It is accepted that the closer the A1C to normal ranges the lower the complication rate. Until achievement of glycemic goals A1C should be measured every 3 months, and in stable patients it should be measured every 6 months.

3 20 Targets of Glycemic Control in Patients with Diabetes Turk JEM 2010; 14: Suppl Table 4-3. The effect of 1% reduction in A1C associated with the risk reduction of development of complications in diabetes Type 1 diabetes (DCCT) Type 2 diabetes (UKPDS) Retinopathy 35% Diabetes-related death 25% Nephropathy 24-44% All-cause mortality 7% Neuropathy 30% Myocardial infarction 18% - Any microvascular complication 35% DCCT Research Group. NEJM 1993;329:977 UKPDS Group. Lancet 1998;352: Fructosamine Fructosamine is a glycosylated protein (over 90% of fructosamine is come from glycosylated albumin). It is an indicator of blood glucose control over the previous 1 to 3 weeks. Serum fructosamine level is a useful marker to assess short-term glucose control in pregnancy, and also provides reliable information in certain hemoglobinopathies Ketonuria and Ketonemia Tests Keton bodies β-hydroxybutyric acid, acetoacetatic acid and acetone are the main keton bodies. Keton bodies are the waste products of fat metabolism. Presence of keton bodies in the blood or urine indicates that foods are not metabolized properly due to insulin deficiency, or insufficient carbohydrate intake (ketones may be elevated mildly in the blood after prolong fasting). Ketones in the urine or blood may indicate DKA. Ketones should be followed when blood glucose excessively increased in type 1 diabetes mellitus, during pregestational diabetes and GDM. Method β-hydroxybutyric acid is measured qualitatively by immersion of test strip in the urine sample or dripping blood onto a test strip. Measurement of keton levels in the blood is a more sensitive method in determining keton products earlier, and in monitoring the response to treatment. When to measure When the blood glucose levels are >300 mg/dl (>200 mg/dl in pregnancy) In the existence of stress factors such as acute diseases, trauma or surgery When nausea, vomiting, abdominal pain and fever is accompanied to hyperglycemia symptoms; also if there is smell of acetone in breath.

4 Turk JEM 2010; 14: Suppl Targets of Glycemic Control in Patients with Diabetes 21 SEMT RECOMMENDATIONS FOR THE TARGETS OF GLYCEMIC CONTROL 1. A1C should be measured every 3 months in patients with diabetes (Class D, evidence-based consensus). 2. A1C may be measured every 6 months in adult patients with optimal glycemic control, stable life style and on appropriate treatment (Class D, evidence-based consensus). 3. Glycemic targets should be determined on individual basis in accordance with patient s characteristics and clinical status to reduce the long-term complications in patients with type 1 and type 2 diabetes (Class D, evidence-based consensus). 4. A1C level should be maintained 6.5% to reduce microvascular complications if patients do not have prominent risk of severe hypoglycemia, and have long life expectancy [Class A, Level 1A evidence (1-3)]. 5. Lowering of A1C should be targeted to reduce macrovascular complications in patients with type 1 diabetes [Class C, Level 3 evidence (4)]. 6. The benefits of decreased A1C should not increase the risks of hypoglycemia and mortality in patients at high risk for CVD [For hypoglycemia: Class A, Level 1A evidence (3,4); For mortality in patients at high risk for CVD: Class A, Level 1A evidence (4)]. 7. To achieve A1C goal 6.5%, blood glucose levels should be as follows; FPG and preprandial PG levels mg/dl [For type 1 diabetes: Class B, Level 2 evidence (1); For type 2 diabetes: Class B, Level 2 evidence (2,5)]. 2 h PG levels <140 mg/dl [For type 1 diabetes: Class D, evidence-based consensus; For type 2 diabetes: Class D, Level 4 evidence (6,7)]. 8. Blood or urine keton testing should be performed in patient with acute disease especially when PG >250 mg/dl (Class D, evidence-based consensus), and in pregnant women when PG >200 mg/dl (Class D, evidence-based consensus). 9. Measurement of keton levels in blood sample should be preferred to determine keton products earlier, and to monitor the response to treatment [Class B, Level 2 evidence (8)]. REFERENCES 1. The Diabetes Control and Complications Trial Research Group. The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin dependent diabetes mellitus. N Engl J Med 1993;329: UK Prospective Diabetes Study (UKPDS) Group. Intensive blood- glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33). Lancet. 1998;352: The ADVANCE Collaborative Group. Intensive blood glucose control and vascular outcomes in patients with type 2 diabetes. New Engl J Med. 2008;358: Nathan DM, Cleary PA, Backlund JY, et al. Intensive diabetes treatment and cardiovascular disease in patients with type 1 diabetes. N Eng J Med 2005;353: Ohkubo Y, Kishikawa H, Araki E, et al. Intensive insulin therapy prevents the progression of diabetic microvascular complications in Japanese patients with non-insulin-dependent diabetes mellitus: a randomized prospective 6-year study. Diabetes Res Clin Pract 1995;28: Monnier L, Lapinski H, Colette C. Contributions of fasting and postprandial plasma glucose increments to the overall diurnal hyperglycemia of type 2 diabetic patients. Diabetes Care 2003;26: Woerle HHJ, Neumann C, Zschau S, et al. Impact of fasting and postprandial glycemia on overall glycemic control in type 2 diabetes. Importance of postprandial glycemia to achieve target HbA1c levels. Diab Res Clin Pract 2007;77: Bektas F, Eray O, Sari R, et al. Point of care blood keton testing of diabetic patients in the emergency department. Endocr Res 2004;30: SELF MONITORING OF BLOOD GLUCOSE (SMBG) ADA Recommendations Type 1 diabetes SMBG should be regarded as an integral part of the treatment of type 1 diabetes. Type 2 diabetes SMBG is a part of insulin therapy. SBMG should be recommended 3-4 times per day in patients receiving multiple insulin injections. SMBG is a useful tool to achieve glycemic targets in patients using insulin or OAD 1-2 times a day, or followed by MNT. SMBG may help to achieve postprandial glycemic targets. Patients should be educated for SMBG and the technique of SMBG and ability to reflect SMBG results to the treatment should be reviewed routinely. There is no consensus on optimal frequency and timing of SMBG in patients with type 2 diabetes. The role of SMBG in stable diet-treated patients with type 2 diabetes is not known.

5 22 Targets of Glycemic Control in Patients with Diabetes Turk JEM 2010; 14: Suppl IDF Recommendations Standard treatment In people with newly diagnosed type 2 diabetes, SMBG should be offered as an integral part of self-management education. Patients with type 2 diabetes on insulin therapy should perform SMBG with glucose meters regularly. Patients with type 2 diabetes on OAD therapy should perform SMBG regularly to monitor 1. hypoglycemia 2.increase of blood glucose caused by medication and lifestyle 3. glycemic changes during intercurrent illnesses. Patients with type 2 diabetes not using insulin or OAD should perform SMBG intermittently to monitor 1. increase of blood glucose caused by lifestyle 2. glycemic changes during intercurrent illnesses. SMBG skills, quality of measurements, interpretation of results and applying them into treatment practice should be reviewed on a yearly basis. Intensive treatment Patients with type 2 diabetes on insulin or OAD therapy should perform SMBG with glucometers regularly. Minimum treatment Patients with type 2 diabetes using insulin only should perform SMBG with glucometer regularly. Frequency of monitoring In type 1 diabetes mellitus, patients on an insulin pump and pregestational diabetic patients should perform SMBG 3 to 4 times a day, before meals and at bedtime, and also as indicated by the treatment protocol. In type 2 diabetic patients as indicated to ensure glycemic control. In patients with GDM at fasting and postprandial (preferably 1 hour later) When planning physical activity; before and after the activity to monitor the effects on metabolic control in patients with type 1 diabetes (and also in type 2 diabetes if necessary) In hypoglycemia; to confirm the diagnosis and to measure the treatment response. In case of acute diseases glycemia should be monitored every 4-6 hours. SEMT RECOMMENDATIONS 1. SMBG is an essential part of diabetes self-management in all insulin-requiring patients [For type 1 diabetic patients: Class A, Level 1 evidence (1); For type 2 diabetic patients: Class C, Level 3 evidence (2)]. 2. Glucometers approved by the international authorities (e.g. IFCC) and calibrated for PG levels, should be used, and a simultaneous measurement with fasting venous plasma sample should be performed at least once a year and also during doubtful conditions to ensure accuracy of the device (Class D, evidence-based consensus). 3. SMBG should be carried out 3-4 times daily before meals, and if needed after a main meal, and also at bedtime once a week, and early morning between 02:00-04:00 am once a month in all patients on a basal-bolus insulin regiment (type 1 or type 2 diabetes, and pregnant women with GDM or pregestational diabetes) [For type 1 diabetic patients: Class A, Level 1 evidence (2-4); For type 2 diabetic patients: Class C, Level 3 evidence (2,5); For pregnant diabetics: Class D, evidence-based consensus]. 4. SMBG should be performed at least once a day at various times in patients with type 2 diabetes using basal insulin plus OAD (Class D, evidence-based consensus). 5. SMBG should be recommended 3-4 times per week to type 2 diabetic patients treated with MNT and OAD according to the level of glycemic control, personal characteristics and type of treatment (Class D, evidence-based consensus). 6. Fasting and 1 h PPG levels should be monitored in pregnant women with diabetes. 7. SMBG should be performed more frequently at the time of treatment changes, during acute illnesses and in patients treated with insulin pump (Class D, evidence-based consensus).

6 Turk JEM 2010; 14: Suppl Targets of Glycemic Control in Patients with Diabetes 23 REFERENCES 1. Epidemiology of severe hypoglycemia in the Diabetes Control and Complications Trial. The DCCT Research Group. Am J Med 1991;90: Karter AJ, Ackerson LM, Darbinian JA, et al. Self-monitoring of blood glucose levels and glycemic control: the Northern California Kaiser Permanent Diabetes Registry. Am J Med 2001;111: Rohlfing CL, Wiedmeyer HM, Little RR, et al. Defining the relationship between plasma glucose and HbA(1c): analysis of glucose profiles and HbA(1c) in the Diabetes Control and Complications Trial. Diabetes Care 2002;25: Sheppard P, Bending JJ, Huber JW. Pre- and post-prandial capillary glucose self-monitoring achieves better glycaemic control than pre-prandial only monitoring. A study in insulin treated diabetic patients. Practical Diabetes Int 2005;22: Murata GH, Shah JH, Hoffman RM, et al; Diabetes Outcomes in Veterans Study (DOVES). Intensified blood glucose monitoring improves glycemic control in stable, insulin-treated veterans with type 2 diabetes: the Diabetes Outcomes in Veterans Study (DOVES). Diabetes Care 2003;26: