Why diabetes and CKD interact
Diabetes is the commonest cause of CKD in the UK (~30% of dialysis patients). When you have both:
- Insulin resistance worsens as GFR falls
- The kidneys clear insulin — so insulin lasts longer in advanced CKD (hypos)
- Kidneys also make glucose (gluconeogenesis) — this falls in CKD
- Some diabetes drugs accumulate (sulfonylureas) — high hypo risk
- HbA1c becomes less accurate (uraemia, anaemia, transfusions can falsely lower it)
- Cardiovascular risk multiplies — heart disease kills more CKD patients than dialysis does
The goal: balance good enough glucose control to prevent eye, nerve and foot damage WITHOUT causing dangerous hypos.
Your HbA1c target
UK GUIDANCE (NICE NG28 + KDIGO 2022):
- Most adults with CKD: 53–58 mmol/mol (7.0–7.5%)
- Frail, elderly, dialysis, multiple hypos: 58–69 mmol/mol (7.5–8.5%)
- Young, fit, early CKD: 48–53 mmol/mol (6.5–7.0%) — only if no hypos
In advanced CKD and dialysis, glycated albumin or continuous glucose monitoring (CGM) is more reliable than HbA1c. Ask your team if you can access a Libre or Dexcom CGM — many CKD patients now qualify.
Kidney Vitality is a daily multivitamin developed by a UK Consultant Nephrologist using renal nutrition principles. It contains no added potassium, magnesium, phosphorus or iron, and no herbal blends. See the formulation.
Safe diabetes drugs in CKD
FIRST-LINE NOW = METFORMIN + SGLT2 INHIBITOR:
Metformin:
- eGFR > 45: full dose
- eGFR 30–45: max 2 g/day
- eGFR < 30: stop (lactic acidosis risk)
- Hold during acute illness, dehydration, contrast scans
SGLT2 inhibitors (dapagliflozin/Forxiga, empagliflozin/Jardiance):
- Reduce CKD progression by ~40%
- Reduce CV death by ~30%
- Continue down to eGFR 20–25
- Side effects: thrush, dehydration, rare DKA — stop in acute illness ('sick day rules')
GLP-1 agonists (semaglutide/Ozempic, dulaglutide/Trulicity, tirzepatide/Mounjaro):
- Safe at all eGFRs
- Weight loss + CV protection
- Side effects: nausea, vomiting — go slow
Insulin:
- Always safe
- Doses usually reduce as eGFR falls
- Long-acting analogues (Lantus, Levemir, Tresiba) preferred — less hypo than NPH
Use With Caution
- Sulfonylureas (gliclazide, glipizide) — high hypo risk, prefer short-acting
- Pioglitazone — fluid retention
- DPP-4 inhibitors — most need dose reduction
Avoid
- Glibenclamide — long-acting hypo risk
Hypoglycaemia in CKD
Hypos (blood glucose < 4.0 mmol/L) are 2–3× more common in CKD because:
- Reduced kidney insulin clearance
- Reduced kidney gluconeogenesis
- Reduced appetite + missed meals
- Drug accumulation
- Dialysis itself (glucose crosses the membrane)
WARNING SIGNS (may be reduced in long-standing diabetes):
- Sweating, shakiness, hunger, anxiety, palpitations
- Confusion, slurred speech, poor concentration
- Severe: seizures, loss of consciousness
TREAT a hypo:
- 15 g fast-acting glucose (5 jelly babies, 4 glucose tabs, 150 ml lucozade)
- Recheck in 15 min, repeat if still < 4
- Then have a starchy snack (toast, biscuit)
- If unconscious — glucagon injection or emergency 999
Report ALL hypos to your team — doses need adjusting.
Practical daily management
Daily
- Test blood glucose before meals if on insulin (target 4–7 pre-meal, 5–9 post-meal)
- CGM if available — much safer in CKD
- Carry a hypo treatment everywhere
- Take medicines as prescribed; don't skip
DIET (renal-diabetic):
- Low glycaemic index carbs (oats, basmati rice, sweet potato in moderation)
- Watch potassium in some 'healthy' foods (avocado, tomato, dried fruit)
- Moderate protein (0.8 g/kg in CKD; higher on dialysis)
- Salt < 6 g/day
- Avoid sugary drinks completely
Annual
- HbA1c every 3–6 months
- Urine ACR and creatinine every 6–12 months
- Eye screening (retinopathy)
- Foot check (podiatrist)
- BP target < 130/80
- Cholesterol — statin recommended
- Flu, COVID, pneumococcal vaccines
