Best Dx/Best Rx: Complications of Diabetes Mellitus

Complications of Diabetes Mellitus

Samuel Dagogo-Jack, MD
University of Tennessee Health Science Center, Memphis, TN

Retinopathy
Nephropathy
Neuropathy

Retinopathy

Definition/Key Clinical Features
Best Tests
Best Therapy
Best References

Definition/Key Clinical Features

Nonproliferative (background) retinopathy

Most common form
Microaneurysms
Dot hemorrhages
Hard lipid exudates
Macular edema

Preproliferative retinopathy

Blot hemorrhages
Soft exudates
Intraretinal microvascular abnormalities
Venous beading
Macular edema

Proliferative retinopathy

Preretinal hemorrhages
Vitreous hemorrhage
Retinal detachment
Macular edema

Best Tests

Dilated and comprehensive eye exam by ophthalmologist

Annually in most diabetic patients
More frequently during pregnancy
Every 2 yr in patients achieving glycemic goals and without cardiovascular disease

Best Therapy

Maintain glucose levels near normal (Hemoglobin A_1c [HbA_1c] < 7%)
Proliferative retinopathy: panretinal scatter photocoagulation
Macular edema: laser treatment
Vitreous hemorrhage that does not clear or with scarring and debris: vitrectomy

Best References

Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Research Group. JAMA 287:2563-9, 2002 [PMID 12020338]

Ferris FL 3rd, et al: N Engl J Med 341:667-78, 1999 [PMID 10460819]

Fong DS, et al: Diabetes Care 26:226-9, 2003 [PMID 12502685]

Willams GA: Adv Stud Ophthalmol 3:13, 2006

Williams R, et al: Eye 18:963-83, 2004 [PMID 15232600]

Nephropathy

Definition/Key Clinical Features
Best Tests
Best Therapy
Best References

Definition/Key Clinical Features

Thickening of capillary basement membrane
Causes microalbuminuria (30–299 mg/day)
Macroalbuminuria (≥ 300 mg/day)
Falling glomerular filtration rate (GFR)
Hypertension
Affects 35%–45% of patients with type 1 diabetes
Affects 10%–20% of patients with type 2 diabetes
Incidence peaks at 15–17 yrs of diabetes, then declines

Best Tests

Urinary albumin measurement, annually
Serum creatinine measurement, annually, with calculated GFR

Best Therapy*

Maintain near-normal glycemic levels (Hb A_1c < 7%)
Maintain good blood pressure control (<130/80 mm Hg)

Restrict dietary sodium
Antihypertensive agents: three or more drugs usually needed

ACE inhibitor or ARB for first drug
Diuretic for second drug
ACE inhibitor or ARB for third drug (if not chosen for first)
Calcium channel blocker: alternative choice
Beta blockers if hx of MI (caution: can mask hypoglycemic symptoms)

Protein restriction if GFR continues to fall
Renal transplantation: better outcomes than dialysis

Best References

Epidemiology of Diabetes Interventions and Complications (EDIC)/Diabetes Control and Complications Trial (DCCT) Study Group: JAMA 290:2159-67, 2003 [PMID 14570951]

Bakris GL, et al: Am J Kidney Dis 36:646-61, 2000 [PMID 10977801]

Mogensen CE, et al: Diabet Med 21:4-17, 2004 [PMID 14706048]

Gross JL, et al: Diabetes Care 28:164-76, 2005 [PMID 15616252]

Karalliedde J, et al: J Hum Hypertens 20:239-53, 2006 [PMID 16452996]

Neuropathy

Definition/Key Clinical Features
Best Tests
Best Therapy
Best References

Definition/Key Clinical Features

Peripheral Neuropathy

Symmetrical
Affects up to 60% of patients
Numbness, tingling in toes and feet
Hypoesthesia or anesthesia
Foot ulcers
Pain

Carpal tunnel and other entrapment syndromes
Autonomic Neuropathy

Erectile dysfunction
Female anorgasmia
Difficulty voiding and urinary retention
Impaired gastric emptying, early satiety, emesis
Diarrhea or constipation
Orthostatic hypotension
Decreased sweating and vasomotor tone in legs
Resting sinus tachycardia

Amyotrophy

Occurs mostly in elderly men
1- to 2-year course
Severe pain, weakness in thigh muscles
Muscle infarcts
Depression, cachexia, weight loss

Best Tests

Examination for distal polyneuropathy at diagnosis and annually

Test for vibration sensation using 128 mHz tuning fork
Test Achilles tendon reflexes
Test sensation with 10 g monofilament

Clinical assessment for autonomic neuropathy: 5 yr after diagnosis in type 1 diabetes, at diagnosis in type 2
Inspection of insensate feet at every visit
Comprehensive foot exam annually

Best Therapy*

Maintain near-normal glycemic levels (HbA_1c < 7%)
Prevent foot ulcers; treat aggressively with broad-spectrum antibiotics
Palliative therapy for neuropathic pain (antidepressants, anticonvulsants, etc.)
Autonomic neuropathy

Gastroparesis: frequent small feedings and parenteral or liquid oral metoclopramide
Feeding jejunostomy
Tetracycline, clonidine, somatostatin for diarrhea
Oral bethanechol, bladder compression, catheterization for bladder dysfunction
Compression stockings, ample sodium intake, fludrocortisone for orthostatic hypotension
For impotence: phosphodiesterase V inhibitors (dangerous in coronary disease), alprostadil, vacuum pumps, penile implants

Best References

Martin CL, et al: Diabetes Care 29:340-4, 2006 [PMID 16443884]

Eaton S, et al: Diabetes Rev 7:312, 1999

Vinik AI: Am J Med 107(suppl 2B):17S, 1999 [PMID 10484041]

Argoff CE, et al: Mayo Clin Proc 81(suppl 4):S3, 2006 [PMID 16608048]

Cavanagh PR, et al: Lancet 366:1725, 2005 [PMID 16291067]

Mark E. Molitch, M.D., has received research support from Sanofi-Aventis, Inc., Eli Lilly & Co., Novo-Nordisk, Inc., and Pfizer, Inc. and has served as a consultant to Sanofi-Aventis, Inc., Novo-Nordisk, Inc., and Abbott Laboratories. Saul Genuth, M.D., has no commercial relationships with manufacturers of products or providers of services discussed in this module.

* To obtain additional drug information, click on the DrugInfo tab in the left column, or click on the following link: http://search.medscape.com/drug-reference-search?queryText=

July 2010