What management approach is recommended for a patient with Type 2 Diabetes Mellitus (DM 2) and psoriasis, with elevated HbA1C and normal renal function?

Management Approach for Type 2 Diabetes with Psoriasis

This patient requires immediate intensification of diabetes therapy with dual or triple combination therapy, and a DPP-4 inhibitor should be strongly considered as it provides dual benefits for both glycemic control and psoriasis management. 1, 2

Current Clinical Status Assessment

Glycemic Control

• The HbA1c of 7.5% exceeds the ADA target of <7.0% and requires treatment intensification beyond current therapy. 3, 1
• The fasting blood glucose of 6.02 mmol/L (108 mg/dL) is relatively well-controlled (target <7.2 mmol/L or <130 mg/dL), but the presence of +4 glucosuria indicates significant hyperglycemia with glucose exceeding the renal threshold. 3
• This pattern suggests inadequate overall glycemic control despite acceptable fasting values, indicating the need for medication adjustment. 1

Renal Function

• The eGFR of 89 mL/min/1.73m² represents mild renal impairment (Stage 2 CKD), which does not significantly limit medication options but requires monitoring. 3
• Annual screening for diabetic kidney disease should continue with urine albumin-creatinine ratio measurements. 3

Anemia Assessment

• The hemoglobin of 109 g/L (10.9 g/dL) and hematocrit of 0.39 (39%) indicate mild anemia, which may be related to chronic disease, iron deficiency, or early diabetic kidney disease. 3
• This requires further evaluation with iron studies, B12, and folate levels to determine etiology and guide treatment.

Treatment Intensification Strategy

Primary Medication Recommendation

Add a DPP-4 inhibitor (such as sitagliptin) to the current regimen as the preferred second-line agent. 4, 5

Rationale for DPP-4 Inhibitor Selection:

• DPP-4 inhibitors provide dual therapeutic benefit in this patient by improving glycemic control AND potentially improving psoriasis. 4
• A case report demonstrated that sitagliptin led to complete resolution of psoriatic plaques within 3 months, independent of glycemic improvement, likely through inhibition of T-cell activation via CD26. 4
• Recent population-based data from Taiwan showed that DPP-4 inhibitor users had a 58% lower risk of incident psoriasis compared to sulfonylurea users (HR 0.422,95% CI 0.273-0.716). 5
• DPP-4 inhibitors carry minimal hypoglycemia risk and are weight-neutral, making them appropriate for this patient. 1, 2

Alternative Second-Line Options (If DPP-4 Inhibitor Unavailable)

• SGLT2 inhibitors (such as empagliflozin 10-25 mg daily) provide cardiovascular and renal protection benefits. 2, 6
• Empagliflozin is effective with eGFR >30 mL/min/1.73m², though efficacy decreases with declining renal function. 6
• SGLT2 inhibitors cause modest weight loss (2-3 kg) and reduce systolic blood pressure by 3-4 mmHg. 6
• Avoid thiazolidinediones despite potential psoriasis benefits due to risks of fluid retention, heart failure, and bone fractures. 5

Metformin Consideration

• If not already on metformin, it should be initiated immediately as the foundation of therapy unless contraindicated. 1, 2
• Metformin is safe with eGFR >45 mL/min/1.73m² and should be dose-adjusted if eGFR falls below this threshold. 1

Monitoring and Follow-Up Protocol

Short-Term Monitoring (3 Months)

• Recheck HbA1c in 3 months to assess treatment effectiveness; if target <7.0% is not achieved, proceed to triple therapy. 1, 2
• Monitor fasting and postprandial glucose levels to guide further adjustments. 3
• Reassess psoriasis severity to evaluate response to DPP-4 inhibitor therapy. 4

Ongoing Surveillance

• Annual comprehensive eye examination by ophthalmologist or optometrist to screen for diabetic retinopathy. 3
• Annual foot examination with 10-g monofilament testing to screen for diabetic neuropathy. 3
• Annual kidney disease screening with urine albumin-creatinine ratio and eGFR. 3
• Monitor hemoglobin and hematocrit every 3-6 months until anemia is resolved. 3

Lifestyle Modifications

Dietary Management

• Limit saturated fat to <7% of total calories and minimize trans fat intake. 3
• Restrict dietary cholesterol to <200 mg/day. 3
• Consume two or more servings of fish per week (excluding commercially fried fish) for omega-3 fatty acids. 3
• Maintain consistent carbohydrate intake at meals to optimize glycemic control. 3

Physical Activity

• Encourage regular physical activity as it improves insulin sensitivity and glycemic control. 3

Alcohol Guidance

• If alcohol is consumed, limit to ≤1 drink/day for women, and always consume with food to prevent hypoglycemia. 3

Cardiovascular Risk Management

Statin Therapy

• Initiate moderate-intensity statin therapy given age 50 years with 10-year diabetes duration. 3
• This reduces cardiovascular risk independent of baseline LDL cholesterol levels. 3

Aspirin Consideration

• Aspirin 75-162 mg daily should be considered if 10-year ASCVD risk exceeds 10%. 3
• Calculate ASCVD risk score to determine appropriateness of aspirin therapy. 3

Critical Pitfalls to Avoid

• Do not use sulfonylureas as second-line therapy in this patient, as they increase psoriasis risk compared to DPP-4 inhibitors (HR 2.37). 5
• Avoid setting overly aggressive HbA1c targets (<6.5%) that increase hypoglycemia risk without proven benefit in patients with 10-year diabetes duration. 3
• Do not delay treatment intensification—clinical inertia is a major barrier to achieving glycemic targets. 7
• Monitor for glucosuria resolution as a marker of improved glycemic control, as persistent +4 glucosuria indicates ongoing hyperglycemia despite acceptable fasting glucose. 3