A Caucasian Man with Newly Diagnosed Type 2 Diabetes and Renal Insufficiency, PART 3

Three months after his initial visit, Mr. Walker and his wife returned for a follow-up visit. Mr. Walker reported he was tolerating the medication well and that he had learned a great deal from the DSME classes taught by a nurse and a dietitian, both of whom were diabetes educators. Although the class format and group support was nice, he found he still had some questions about how much protein and salt he should eat due to his kidney disease and hypertension. 

He reported that even though he learned that sitagliptin is unlikely to cause hypoglycemia, he is now self-monitoring his blood sugars occasionally after meals, and this was helping him adjust his diet and portion sizes. However, he was still having difficulty finding time to exercise, but he was walking with his wife after dinner for 20-30 minutes several days a week.

His wife said she was much happier now that her husband was taking better care of himself and she reported that her A1C had also improved.

Based on Mr. Walker's presentation and laboratory values at the 3 month follow-up visit, what changes would you recommend?

A.   Continue the current medication regimen

B.   Add glipizide ER 5 mg daily to improve glycemic control

C.   Increase simvastatin to 80 mg daily to reduce risk of cardiovascular disease

D.   Encourage further lifestyle interventions

E.   Answers B and D

Best Answer: E - Mr. Walker can benefit from further improvement in his glycemic control, and increased lifestyle intervention may assist him in achieving that goal.

Question 3 Explanation: Glycemic control 

Based on the information gathered at Mr. Walker's follow-up visit, an increase in therapy is needed to manage his hyperglycemia.  Encouraging further lifestyle interventions is also recommended. 

Mr. Walker's glycemic control has improved, as shown by his decreased A1C and the improvements in his average blood glucose readings -- particularly his postprandial average. His glycemic control, however, is still above goal.

The addition of glipizide ER 5 mg daily, a sulfonylurea, is an inexpensive treatment that may enhance his insulin secretion and thus improve his glycemic control. However, the metabolism and secretion of glipizide may be slowed in patients with renal or hepatic insufficiency, which may increase the risk of hypoglycemia. Therefore, his glipizide dose should be advanced carefully due to his renal insufficiency. He should be instructed to closely monitor his glucose levels and be educated in how to treat hypoglycemia should it occur.

Question 3 Explanation: Lifestyle interventions 

An increase in therapy is needed to manage his hyperglycemia; encouraging further lifestyle interventions is also recommended. 

Because sulfonylureas can cause weight gain, additional lifestyle interventions should be encouraged. 

• Mr. Walker should be praised for the 5 lbs he lost since his previous visit and encouraged to make further diet modifications
• An individual session for Mr. Walker and his wife with the dietitian from his DSME class might be helpful to provide more detailed instruction on his specific diet needs
• It may also be helpful to ask him how he could increase his activity level and offer suggestions if needed

Question 3 Explanation: Cardiovascular disease risk

An increase in therapy is needed to manage his hyperglycemia; encouraging further lifestyle interventions is also recommended.

Based on his lipid profile results, Mr. Walker has achieved the LDL, HDL, and triglyceride goals for patients with diabetes on his current dose of medication. Therefore, increasing his dose of simvastatin from 40 mg to 80 mg is not indicated. 

If Mr. Walker had presented with a history of a cardiovascular event or an acute coronary syndrome, his LDL goal would be changed to <70 mg/dL and an increase in statin therapy would be recommended

Mr. Walker's physician made the following treatment changes and recommendations: 

• A prescription was written for glipizide ER 5 mg daily
• All other medications were continued
• He was instructed on the symptoms and treatment for hypoglycemia, and was told to perform additional self-monitoring of his blood glucose if he felt it might be low
• Further diet and lifestyle interventions were encouraged
• He was scheduled for another follow-up visit in 3 months

This patient presented 6 months after his type 2 diabetes diagnosis with

• worsening glycemic control
• poorly controlled hypertension
• renal insufficiency
• 1+ ankle edema
• stable angina

Improving both glycemic control and blood pressure was a priority to prevent further decline in his kidney function and decrease his risk of cardiovascular and microvascular diabetes complications, such as retinopathy and peripheral vascular disease. 

Mr. Walker was not taking medication for his type 2 diabetes and it was important to find a medication that was not contraindicated due to his renal insufficiency.

Sitagliptin, a DPP-4 inhibitor, was selected initially as monotherapy because of its effectiveness in treating postprandial hyperglycemia, its low incidence of side effects, and its neutral effect on body weight. It was started at a reduced dose of 50 mg due to Mr. Walker's renal insufficiency. 

After 3 months of sitagliptin therapy, glycemic control had improved, with an A1C of 7.6%, but this was still above goal. Therefore, a sulfonylurea was added as combination therapy. The addition of a sulfonylurea is one of the therapies recommended in the ACE/AACE Roadmap for treated patients with A1C levels of 6.5%-8.5%.

Mr. Walker's hypertension improved to <130/80 mmHg and his ankle edema resolved with the addition of furosemide 40 mg daily. In addition, the improvement in his glycemic control and the continuation of simvastatin brought his triglycerides to 145 mg/dL, which is within goal. 

Initiation of medical nutrition therapy was also recommended and contributed to the improvement in Mr. Walker's weight and glycemic control. This therapy was intensified at the follow-up visit because the patient was receptive to further education and because he was being started on a medication that could lead to weight gain as well as increase his risk of hypoglycemia. 

Future follow-up visits will determine the success of these medication and lifestyle changes on Mr. Walker's glycemic control, hypertension, renal insufficiency, and cardiovascular risk.

The articles below may be of value in continuing your education on the topics discussed in this case study.

1. ACE/AACE Diabetes Roadmap Task Force. Road maps to achieve glycemic control in type 2 diabetes mellitus. Endocr Pract. 2007;13:260-268.
2. Ahmann AJ, Riddle MC.  Insulin therapy in type 2 diabetes mellitus. In: Leahy JL, Cefalu WT eds. Insulin Therapy. New York, NY:Marcel Dekker, Inc.; 2002:113.125.
3. American Diabetes Association. Standards of medical care in diabetes–2009. Diabetes Care. 2009;32(Suppl 1):S13-S61.
4. Buse JB, Ginsberg HN, Bakris GL, et al. Primary prevention of cardiovascular diseases in people with diabetes mellitus: A scientific statement from the American Heart Association and the American Diabetes Association. Diabetes Care. 2007;30:162-172.
5. Holman RR, Paul SK, Bethel MA, et al. 10-year follow-up of intensive glucose control in type 2 diabetes. N Engl J Med. 2008;359:1577-1589.
6. Monnier L, Lapinski H, Colette C. Contributions of fasting and postprandial plasma glucose increments to the overall diurnal hyperglycemia of type 2 diabetic patients: Variations with increasing levels of HbA1c. Diabetes Care 2003;26:881-885.
7. Nathan DM, Buse JB, Davidson MB, et al. Management of hyperglycaemia in type 2 diabetes mellitus: a consensus algorithm for the initiation and adjustment of therapy: update regarding the thiazolidinediones. Diabetologia. 2008;51:1-11.
8. Physicians' Desk Reference 63^rd edn. Thomson PDR: Montvale, NJ (2009).
9. Pittas AG, Lau J, Hu FB, et al. The role of vitamin D and calcium in type 2 diabetes. A systematic review and meta-analysis.  J Clin Endocrinol Metab. 2007;92:2017-2029.
   
10. 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;352:837-853.
    
11. Yki-Jarvinen H, Ryysy L, Nikkila K, et al.  Comparison of bedtime insulin regimens in patients with type 2 diabetes mellitus: a randomized, controlled trial.  Ann Intern Med. 1999;130:389-396.