DM complications - Renal complications

Question 1

The prognosis of individuals with diabetes on dialysis

Answer 1

Poor

Question 2

Albuminuria in individuals with DM is associated with an increased risk of ____

Answer 2

Cardiovascular disease

Question 3

T/F. Individuals with diabetic nephropathy commonly have diabetic retinopathy

Answer 3

True

Question 4

Like other microvascular complications, the pathogenesis of diabetic nephropathy is related to ____; the mechanisms by which it leads to diabetic nephropathy is ____

Answer 4

• Chronic hyperglycemia
• Incompletely defined, but involve the effects of:
  
  • Soluble factors (growth factors, angiotensin II, endothelin, advanced glycation end products [AGEs]),
  • Hemodynamic alterations in the renal microcirculation (glomerular hyperfiltration or hyperperfusion, increased glomerular capillary pressure)
  • Structural changes in the glomerulus (increased extracellular matrix, basement membrane thickening, mesangial expansion, fibrosis)
• Note:*
• Some of these effects may be mediated through angiotensin II receptors

Question 5

Risk factors in the development of diabetic nephropathy

Answer 5

• Smoking
• Family history of diabetic nephropathy
  *

Question 6

The natural history of diabetic nephropathy

Answer 6

• First years after the onset of DM
  
  • Glomerular hyperperfusion and renal hypertrophy occur
  • Associated with an increase of the estimated glomerular filtration rate (GFR)
• During the first 5 years of DM
  
  • Thickening of the glomerular basement membrane, glomerular hypertrophy, and mesangial volume expansion occur as the GFR returns to normal
• After 5–10 years
  
  • Many individuals begin to excrete small amounts of albumin in the urine

Question 7

Diabetic kidney disease refers to:

Answer 7

• Albuminuria and reduced GFR
  
  • Increased urinary protein excretion (spot urinary albumin-to-creatinine ratio >30 mg/g Cr)
  • GFR < 60 mL/min/1.73 m²

Question 8

T/F. Once there is marked albuminuria and a reduction in GFR, the pathologic changes are likely irreversible

Answer 8

True

Question 9

The nephropathy that develops in type 2 DM differs from that of type 1 DM in the following respects:

Answer 9

1. Albuminuria may be present when type 2 DM is diagnosed, reflecting its long asymptomatic period
2. Hypertension more commonly accompanies albuminuria; and
3. Albuminuria may be less predictive of diabetic kidney disease

• Note:*
• Albuminuria in type 2 DM may be secondary to factors unrelated to DM, such as hypertension, congestive heart failure (CHF), prostate disease, or infection

Question 10

Albuminuria definition

Answer 10

Increased urinary protein excretion (spot urinary albumin-to-creatinine ratio > 30 mg/g Cr)

Question 11

Screening for albuminuria should commence when?

Answer 11

• 5 years after the onset of type 1 DM; and
• At the time of diagnosis of type 2 DM

Question 12

Type of renal tubular acidosis that may occur in type 1 or 2 DM

Answer 12

Type IV renal tubular acidosis (hyporeninemic hypoaldosteronism)

Question 13

Patients with DM are predisposed to radiocontrast-induced nephrotoxicity; risk factors for radiocontrast-induced nephrotoxicity
are:

Answer 13

Preexisting nephropathy and volume depletion

Question 14

Things to remember in individuals with DM undergoing radiographic procedures with contrast dye

Answer 14

• Well hydrated before and after dye exposure
• Serum creatinine should be monitored for 24–48 h following the procedure
• Metformin should be held until postintervention confirmation of preserved kidney function

Question 15

Interventions effective in slowing progression of albuminuria include:

Answer 15

1. Improved glycemic control
2. Strict blood pressure control
3. Administration of an ACE inhibitor or ARB
4. Dyslipidemia should also be treated

• Note:*
• However, once there is a large amount of albuminuria, it is unclear whether improved glycemic control will slow progression of renal disease

Question 16

During the later phase of declining renal function, insulin requirements may fall. Why?

Answer 16

The kidney is a site of insulin degradation

• Note:*
• As the GFR decreases with progressive nephropathy, the use and dose of glucose-lowering agents should be reevaluated

Question 17

Glucose-lowering medications that are contraindicated in advanced renal insufficiency

Answer 17

• Sulfonylureas
• Metformin

Question 18

BP target

Answer 18

• < 140/90 mmHg in individuals with diabetes
• < 130/80 in individuals at increased risk for CVD and CKD progression

Question 19

T/F. There is no benefit of intervention prior to onset of albuminuria

Answer 19

True

Question 20

If use of either ACE inhibitors or ARBs is not possible or the blood pressure is not controlled, then:

Answer 20

• Other drugs should be used
  
  • Diuretics
  • Calcium channel blockers (nondihydropyridine class)
  • Beta blockers

Question 21

When to refer

• Nephrology consultation
• Transplant evaluation

Answer 21

• Nephrology consultation
  
  • When albuminuria appears and when the estimated GFR is <30 mL/min per 1.743 m²
• ^​Transplant evaluation
  
  • When GFR approaches 20 mL/min per 1.743 m²

Question 22

As compared with nondiabetic individuals,
hemodialysis in patients with DM is ____

Answer 22

• Associated with more frequent complications, such as:
  
  • Hypotension (due to autonomic neuropathy or loss of reflex tachycardia)
  • More difficult vascular access
  • Accelerated progression of retinopathy