Case Study: Patient with Diabetes, CKD, and Hypertension
Clinical Presentation
A 58-year-old male with type 2 diabetes (12 years), stage 3b CKD (eGFR 38 mL/min/1.73 m²), and hypertension presents for optimization of his chronic disease management. Current medications include metformin 1000 mg twice daily and lisinopril 10 mg daily. Recent labs show HbA1c 8.4%, blood pressure 148/92 mmHg, serum creatinine 1.9 mg/dL, potassium 4.6 mEq/L, and urine albumin-to-creatinine ratio 450 mg/g.
Board-Style Questions and Answers
Question 1: What is the MOST appropriate immediate medication adjustment?
A. Discontinue metformin and start insulin
B. Increase lisinopril to maximum tolerated dose and add SGLT2 inhibitor
C. Add amlodipine and continue current regimen
D. Switch lisinopril to losartan
Correct Answer: B
The most critical immediate intervention is maximizing ACE inhibitor therapy and initiating an SGLT2 inhibitor, as this patient has diabetes, hypertension, and significant albuminuria (≥300 mg/g). 1
Rationale:
ACE inhibitor titration is mandatory: With albuminuria ≥300 mg/g and eGFR <60 mL/min/1.73 m², this patient requires the highest tolerated dose of ACE inhibitor or ARB (Grade A recommendation). 2 The current lisinopril 10 mg daily is subtherapeutic and must be titrated upward. 1
SGLT2 inhibitor initiation is non-negotiable: With eGFR 38 mL/min/1.73 m² (≥20), an SGLT2 inhibitor should be started immediately regardless of glycemic control status, as it provides kidney protection, cardiovascular benefits, and reduces heart failure hospitalizations independent of glucose-lowering effects. 1 These benefits persist even as eGFR declines and should be continued until dialysis. 1
Metformin dose adjustment, not discontinuation: At eGFR 30-44 mL/min/1.73 m², metformin should be reduced to 1000 mg daily (not discontinued), as discontinuation only occurs when eGFR falls below 30 mL/min/1.73 m². 1 The patient's current dose of 2000 mg daily exceeds the safe threshold.
Monitoring requirements: Serum creatinine and potassium must be checked within 2-4 weeks after increasing ACE inhibitor dose, and therapy should continue unless creatinine rises >30% within 4 weeks. 1
Question 2: What is the target blood pressure for this patient?
A. <140/90 mmHg
B. <130/80 mmHg
C. <120/80 mmHg
D. <125/75 mmHg
Correct Answer: B
For patients with diabetes, hypertension, and albuminuria, the blood pressure target is <130/80 mmHg. 2, 3
Rationale:
Diabetes-specific target: The ADA recommends <130/80 mmHg for patients with diabetes, hypertension, and high cardiovascular risk (which includes those with CKD and albuminuria). 2
CKD considerations: While KDIGO 2021 suggests <120 mmHg systolic based on standardized office measurement for CKD patients, this recommendation was based on trials excluding diabetic patients and carries caveats for safety in the diabetic population. 2 The consensus target of <130/80 mmHg balances efficacy with safety in diabetic CKD. 3
Albuminuria amplifies benefit: Blood pressure control is critical for reducing albuminuria progression and preventing cardiovascular events in this high-risk population. 2
Question 3: The patient returns in 3 weeks. Creatinine has increased from 1.9 to 2.3 mg/dL (21% rise), and potassium is 5.2 mEq/L. What is the MOST appropriate next step?
A. Discontinue ACE inhibitor immediately
B. Continue ACE inhibitor, implement dietary potassium restriction and add loop diuretic
C. Reduce ACE inhibitor dose by 50%
D. Switch to calcium channel blocker
Correct Answer: B
Do not discontinue the ACE inhibitor for a creatinine rise <30% or mild hyperkalemia—instead, manage potassium through dietary modification, diuretics, sodium bicarbonate, or GI cation exchangers. 1
Rationale:
Creatinine rise is acceptable: A 21% increase in creatinine is below the 30% threshold that warrants evaluation for acute kidney injury, volume depletion, or renal artery stenosis. 1 This degree of rise is expected with effective RAS blockade and does not require discontinuation. 2
Hyperkalemia management without stopping ACEi: Potassium 5.2 mEq/L is mild hyperkalemia. First-line management includes dietary potassium restriction (<2 g/day), adding a loop diuretic to enhance potassium excretion, and potentially sodium bicarbonate if metabolic acidosis is present. 1 Discontinuing the ACE inhibitor would eliminate critical renoprotection in a patient with significant albuminuria.
Monitoring intensity: Recheck creatinine and potassium in 1-2 weeks after implementing potassium management strategies. 2, 1
Question 4: After 3 months of optimized therapy (maximized ACE inhibitor, SGLT2 inhibitor, reduced metformin), HbA1c remains 7.8%. What is the NEXT best medication to add?
A. Sulfonylurea
B. GLP-1 receptor agonist
C. DPP-4 inhibitor
D. Basal insulin
Correct Answer: B
Add a GLP-1 receptor agonist when glycemic targets are not met with metformin and SGLT2 inhibitors, as GLP-1 agonists provide additional cardiovascular and potential renal benefits. 1
Rationale:
GLP-1 agonist superiority: GLP-1 receptor agonists (such as liraglutide) have demonstrated cardiovascular mortality reduction and are safe in CKD. 4 The LEADER trial showed liraglutide reduced major adverse cardiac events (HR 0.87,95% CI 0.78-0.97) and cardiovascular death (HR 0.78,95% CI 0.66-0.93) in patients with diabetes and established cardiovascular disease, including those with CKD. 4
Avoid sulfonylureas: Sulfonylureas increase hypoglycemia risk, particularly when combined with SGLT2 inhibitors, and lack cardiovascular or renal protective benefits. 1
DPP-4 inhibitors are inferior: While safe in CKD, DPP-4 inhibitors provide less robust glycemic control and lack the cardiovascular benefits of GLP-1 agonists. 1
Insulin is premature: Basal insulin should be reserved for patients who fail triple therapy or have severe hyperglycemia. Adding insulin at this stage increases hypoglycemia risk without the cardiovascular benefits of GLP-1 agonists. 1
Question 5: Which additional medication should be considered if albuminuria remains ≥300 mg/g despite 6 months of optimized ACE inhibitor and SGLT2 inhibitor therapy?
A. Spironolactone
B. Finerenone
C. Hydralazine
D. Beta-blocker
Correct Answer: B
Consider adding finerenone (a nonsteroidal mineralocorticoid receptor antagonist) for patients with type 2 diabetes who have persistent albuminuria ≥30 mg/g despite first-line therapy and normal potassium levels. 1
Rationale:
Finerenone's unique role: Finerenone is a nonsteroidal MRA that provides additional renoprotection and cardiovascular benefit beyond ACE inhibitors and SGLT2 inhibitors in diabetic kidney disease with persistent albuminuria. 1
Potassium monitoring is critical: Finerenone can cause hyperkalemia, so it should only be added when potassium is normal and requires close monitoring. 1 Given this patient's prior potassium of 5.2 mEq/L, potassium must be normalized before initiation.
Spironolactone carries higher hyperkalemia risk: While steroidal MRAs like spironolactone have renoprotective effects, they carry a higher risk of hyperkalemia compared to finerenone, particularly when combined with ACE inhibitors. 1
Question 6: What is the target HbA1c range for this patient?
A. <6.5%
B. 6.5-7.0%
C. 6.5-8.0%
D. 7.0-9.0%
Correct Answer: C
Target HbA1c between 6.5% and 8.0%, individualized based on hypoglycemia risk, life expectancy, comorbidities, and patient preferences. 2, 1
Rationale:
KDIGO and ADA consensus: For patients with diabetes and CKD, an individualized HbA1c target of 6.5-8.0% balances microvascular risk reduction with hypoglycemia prevention. 2 This range has been associated with improvements in survival, cardiovascular outcomes, and microvascular endpoints, as well as lower risk of CKD progression. 2
Patient-specific factors: This 58-year-old with stage 3b CKD has moderate life expectancy and moderate hypoglycemia risk (on metformin, SGLT2 inhibitor, and potentially GLP-1 agonist). A target closer to 7.0-7.5% is reasonable. 1
Monitoring frequency: Check HbA1c every 3 months when therapy changes or targets are not met, and at least twice yearly in stable patients. 1
Question 7: What dietary protein intake should be recommended?
A. 0.6 g/kg/day
B. 0.8 g/kg/day
C. 1.2 g/kg/day
D. 1.5 g/kg/day
Correct Answer: B
Limit protein intake to 0.8 g/kg/day for patients with diabetes and CKD not on dialysis. 2, 1
Rationale:
Evidence-based threshold: For stage 3-5 non-dialysis-dependent CKD, dietary protein intake of 0.8 g/kg/day (the recommended daily allowance) slows GFR decline compared to higher protein intake. 2
Avoid excessive protein: Higher protein intake (>20% of daily calories or >1.3 g/kg/day) has been associated with increased albuminuria, more rapid kidney function loss, and cardiovascular mortality. 2
Sodium restriction is equally important: Restrict sodium intake to <2 g/day (<90 mmol/day or <5 g sodium chloride/day) to optimize blood pressure control and reduce albuminuria. 1, 3
Question 8: When should this patient be referred to nephrology?
A. Immediately, given eGFR <45 mL/min/1.73 m²
B. When eGFR falls below 30 mL/min/1.73 m²
C. When eGFR falls below 20 mL/min/1.73 m²
D. Only if dialysis is imminent
Correct Answer: B
Refer to nephrology when eGFR falls below 30 mL/min/1.73 m² (stage 4 CKD), as patients require monitoring for CKD complications and preparation for renal replacement therapy. 2, 5, 6
Rationale:
Stage 4 CKD threshold: Patients with eGFR <30 mL/min/1.73 m² are at high risk of CKD progression and require nephrology co-management for complications including hyperkalemia, metabolic acidosis, anemia, and mineral bone disease. 2, 5
Severe albuminuria also warrants referral: This patient's albuminuria of 450 mg/g (≥300 mg/g) is another indication for nephrology referral, though primary care can initiate treatment first. 5, 6
Current eGFR 38 mL/min/1.73 m²: While this patient is stage 3b CKD, primary care can manage with close monitoring. However, if eGFR declines to <30 or albuminuria worsens despite optimal therapy, nephrology referral becomes mandatory. 6
Question 9: Which additional cardiovascular risk reduction medication is indicated?
A. Aspirin 81 mg daily
B. High-intensity statin
C. Clopidogrel 75 mg daily
D. Omega-3 fatty acids
Correct Answer: B
Initiate statin therapy in all patients with type 1 or type 2 diabetes and CKD for cardiovascular risk reduction. 1, 3
Rationale:
Universal statin indication: Patients with diabetes and CKD have extremely high cardiovascular risk, and statin therapy reduces cardiovascular events and mortality. 1, 3 High-intensity statins (atorvastatin 40-80 mg or rosuvastatin 20-40 mg) are preferred for maximal LDL reduction. 3
No dose adjustment needed: Statins do not require dose adjustment for eGFR 38 mL/min/1.73 m² and are safe in CKD. 3
Aspirin is not universally indicated: Aspirin for primary prevention in diabetes is controversial and should be reserved for patients with additional cardiovascular risk factors or established ASCVD. 3
Question 10: What is the MOST important lifestyle modification to emphasize?
A. Weight loss of 10% body weight
B. Tobacco cessation
C. Moderate-intensity exercise 150 minutes per week
D. Mediterranean diet
Correct Answer: B
Strongly recommend tobacco cessation for all patients who use tobacco products, as smoking accelerates CKD progression and increases cardiovascular mortality. 1
Rationale:
Tobacco's devastating impact: Smoking is a modifiable risk factor that accelerates diabetic kidney disease progression, worsens albuminuria, and dramatically increases cardiovascular risk. 1, 7 Cessation is the single most impactful lifestyle intervention.
Exercise is also critical: Moderate-intensity physical activity for at least 150 minutes per week (or to a level compatible with cardiovascular and physical tolerance) improves glycemic control, blood pressure, and cardiovascular fitness. 1, 3
Dietary modifications matter: Sodium restriction (<2.3 g/day), protein moderation (0.8 g/kg/day), and appropriate carbohydrate management are essential. 1, 3
Weight loss benefits: For overweight/obese patients, weight loss improves glycemic control, blood pressure, and albuminuria, but tobacco cessation takes priority. 3
Key Clinical Pearls
Triple therapy is standard: SGLT2 inhibitor + maximized ACE inhibitor/ARB + metformin (if eGFR ≥30) forms the foundation of diabetic CKD management. 1
Don't fear creatinine bumps: Up to 30% creatinine rise after starting/titrating ACE inhibitors is acceptable and reflects effective hemodynamic changes, not kidney injury. 1
Hyperkalemia is manageable: Implement dietary restriction, diuretics, and potassium binders before discontinuing life-saving RAS blockade. 1
SGLT2 inhibitors work at low eGFR: Continue SGLT2 inhibitors until dialysis, as renal and cardiovascular benefits persist even when glucose-lowering effects diminish. 1
Monitor intensively: Check creatinine and potassium within 2-4 weeks of any RAS blocker adjustment, and HbA1c every 3 months until stable. 1