Prevention of diabetic nephropathy

The use of lysosomal enzymuria in the early detection and monitoring of the progression of diabetic nephropathy

Recent acquisitions on the early detection and monitoring of the progression of diabetic complications (nephropathy) using the techniques of enzymology (lysosomal enzymes) are reviewed. it appears that the kidney is the principal source of urinary lysosomal enzymes. Urinary samples for lysosomal enzyme determination can be either 24-hour or spot-collection. The use of synthetic substrates (4-methylumbelliferyl substrates) provides an easy, inexpensive, sensitive and highly reproducible method of lysosomal enzyme assay. It is recommended that more than one enzyme be assayed in the process. The use of fractional enzyme excretion (FEE) ratios is further recommended. The urinary lysosomal glycosidases investigated and found to be of particular diagnostic value in the early detection of diabetic nephropathy include N-acetyl-β-D-glucosaminidase (β-hexosaminidase, NAG), β-glucuronidase and β-galactosidase, with NAG being the most useful indicator. Urinary NAG can be used in monitoring the progression of diabetic nephropathy. The fluorimetric assay of lysosomal glycosidases is particuarly recommended in developing countries since it is simple, sensitive and inexpensive.

Diabetes care credit system: a model for comprehensive and optimal diabetes care

OBJECTIVE

To introduce a "credit system," which empowers patients with diabetes to share in the implementation of guidelines with the health-care provider and provides credits for achievement of health variables considered essential for optimal diabetes care.

METHODS

We describe the credit system and the points offered for achievement of variables that assess lifestyle, glycohemoglobin, blood pressure, lipid values, measurement of urinary albumin, annual physical examination, dilated eye examination, foot examination, and electrocardiogram, use of antiplatelet therapy, and use of angiotensin receptor blocker (ARB) or angiotensin-converting enzyme (ACE) inhibitor therapy. The patient's knowledge of diabetes and nutrition was also assessed. Patients with diabetes mellitus were enrolled in the credit program during their scheduled office visits. Results were compared with those in a control group.

RESULTS

The study enrolled 613 patients (303 male and 310 female patients), with a mean age of 59.91 +/- 13.57 years (range, 16 to 90). The control group consisted of 119 patients with diabetes (63 men and 56 women; mean age, 55.94 +/- 14.83 years) not participating in the credit system. One year after initiation of the program, analysis of the study group demonstrated high rates of implementation of guidelines: complete physical examination, 94%; foot examination, 89%; dilated eye examination, 77%; blood pressure less than 135/85 mm Hg, 78%; hemoglobin A1c less than 6%, 7%, and 8%, 26%, 58%, and 82%, respectively; serum triglycerides less than 200 mg/dL, 61%; low-density lipoprotein cholesterol less than 100 mg/dL, 49%; high-density lipoprotein cholesterol more than 35 mg/dL, 76%; use of antiplatelet therapy, 60%; quantitative urinary albumin screening, 74%; and use of ACE inhibitors or ARB, 44%. These rates of achievement of established variables for hemoglobin A1c, serum lipids, blood pressure, antiplatelet therapy, and measurement of urinary albumin were significantly higher than those in the control subjects.

CONCLUSION

The described credit system demonstrates an effective and practical means to implement and achieve the necessary guidelines and target variables that are intended to lead to optimal diabetes and cardiovascular outcomes.

Forecast of the number of patients with end-stage renal disease in the United States to the year 2010

As the United States end-stage renal disease (ESRD) program enters the new millennium, the continued growth of the ESRD population poses a challenge for policy makers, health care providers, and financial planners. To assist in future planning for the ESRD program, the growth of patient numbers and Medicare costs was forecasted to the year 2010 by modeling of historical data from 1982 through 1997. A stepwise autoregressive method and exponential smoothing models were used. The forecasting models for ESRD patient numbers demonstrated mean errors of -0.03 to 1.03%, relative to the observed values. The model for Medicare payments demonstrated -0.12% mean error. The R(2) values for the forecasting models ranged from 99.09 to 99.98%. On the basis of trends in patient numbers, this forecast projects average annual growth of the ESRD populations of approximately 4.1% for new patients, 6.4% for long-term ESRD patients, 7.1% for dialysis patients, 6.1% for patients with functioning transplants, and 8.2% for patients on waiting lists for transplants, as well as 7.7% for Medicare expenditures. The numbers of patients with ESRD in 2010 are forecasted to be 129,200 +/- 7742 (95% confidence limits) new patients, 651,330 +/- 15,874 long-term ESRD patients, 520,240 +/- 25,609 dialysis patients, 178,806 +/- 4349 patients with functioning transplants, and 95,550 +/- 5478 patients on waiting lists. The forecasted Medicare expenditures are projected to increase to $28.3 +/- 1.7 billion by 2010. These projections are subject to many factors that may alter the actual growth, compared with the historical patterns. They do, however, provide a basis for discussing the future growth of the ESRD program and how the ESRD community can meet the challenges ahead.

Dealing with diabetic nephropathy

Nephropathy may develop in patients with type 1 diabetes because poor glycemic control produces effects that eventually lead to glomerular scarring and renal failure. The worse and more prolonged the hyperglycemia, the greater the risk of diabetic nephropathy. In patients with type 2 diabetes, hyperglycemia, as well as insulin resistance and generalized vascular disease, is involved in the pathogenesis of nephropathy. The glomerular changes of early diabetic nephropathy can be identified only by renal biopsy or by testing for microalbuminuria. Once macroalbuminuria occurs (albumin excretion rate, > 300 mg/day), usually after type 1 diabetes has been present for 10 to 15 postpubertal years, end-stage renal disease is almost inevitable. However, aggressive control of hypertension in diabetic patients without microalbuminuria helps avoid nephropathy, and tight glycemic control in those with microalbuminuria can avoid or delay its onset. Even when macroalbuminuria is present, treatment can prolong renal function. Aggressive antihypertensive therapy, especially with ACE inhibitors, can reduce renal decline by half. Avoiding circumstances that may damage the kidneys (e.g., use of radiocontrast materials or nephrotoxic drugs, dehydration, hyperlipidemia, urinary tract infection, buildup of AGEs) is critical. Some treatment methods are controversial (dietary protein restriction) or still under investigation (use of injected or oral heparin) but may help delay renal transplantation or dialysis.