LIPOPROTEIN AND PRERETINAL
What is the best way to manage a high lipoprotein(a) and preretinal membrane in a 70-year-old woman with mild, controlled hypertension, moderate exogenous obesity, and mild type 2 diabetes? She also has multinodular goiter, which was negative for cancer on biopsy. The patient’s maternal grandmother developed type 2 diabetes at age 80. Current medications include irbesartan/hydrochlorothiazide (Avalide) 300 mg/12.5 mg, ezetimibe/simvastatin (Vytorin 10/20), metformin 500 mg, and levothyroxine (Levoxyl) 100 µg.
An attempt at shrinking the thyroid nodules by raising the Levoxyl dose was unsuccessful, and the dose was returned to her usual 100 µg.
—Joel A. Moskowitz, MD, La Jolla, Calif.
Management approaches to your patient’s high lipoprotein(a) and diabetic retinopathy overlap in a somewhat complementary fashion. Treatment of the elevated lipoprotein(a) should first focus on lowering LDL, according to Adult Treatment Panel III guidelines. Her diagnosis of comorbid diabetes means her LDL goal should be <100 mg/dL. If lipoprotein(a) levels remain high, there are some data to suggest the use of nicotinic acid or neomycin (Arch Intern Med. 2000;160:1177-1184). These agents have been shown to reduce lipoprotein(a) levels, but data regarding beneficial clinical outcomes are limited. Management of her diabetic retinopathy focuses on her other metabolic risk factors, namely tight glycemic control and aggressive BP control.
The degree of protection against development and progression of diabetic retinopathy has been demonstrated to correlate directly with the degree of diabetic control. The United Kingdom Prospective Diabetes Study (UKPDS) showed a significant reduction in the development of diabetic retinopathy with more aggressive BP lowering. Literature also suggests that the use of ACE inhibitors may have an even more specific effect similar to the prevention of nephropathy. Finally, the Steno-2 trial showed that aggressive, multifactorial risk reduction focusing on all of your patient’s metabolic derangements (hypertension, hyperlipidemia, and diabetes with target-organ damage) might have significant benefit compared with standard therapy (N Engl J Med. 2003;348:383-393). The target for BP in this trial was <140/85 mm Hg, and the target for hemoglobin A1c was <6.5%.
In addition to focusing on aggressive metabolic control as noted, you may consider adding an aspirin to her daily regimen. Data suggest no benefit from the use of aspirin with regard to retinopathy, but it appears to be safe and might confer some cardiovascular benefit.
—Christopher Ruser, MD (101-17)