title: Foot insensitivity is associated with renal function decline in patients with type 2 diabetes: a cohort study.
abstract: BACKGROUND
  Identifying patients with diabetes at increased risk of chronic kidney disease (CKD) is essential to prevent/slow the progression to end-stage renal disease (ESRD). CKD and diabetic peripheral neuropathy (DPN) share common mechanisms. Hence, we aimed to examine the relationship between foot insensitivity and CKD in patients with Type 2 diabetes.
  
  
  METHODS
  A prospective observational cohort study in adults with Type 2 diabetes. Patients with ESRD were excluded. Foot insensitivity was assessed using the 10-g monofilament test. Renal function was assessed using estimated glomerular filtration rate (eGFR) based on the MDRD equation. Albuminuria was defined as the presence of urinary albumin/creatinine ratio (ACR) >3.4 mg/mmol.
  
  
  RESULTS
  Two hundred and twenty eight patients were recruited and followed-up for 2.5 years. One hundred and ninety patients (83.4%) had eGFR ≥ 60 ml/min/1.73 m2. Seventy six (33.3%) patients had foot insensitivity (i.e. abnormal monofilament test). Patients with foot insensitivity had lower eGFR and higher prevalence of albuminuria compared to patients with normal monofilament test. After adjustment for age, gender, ethnicity, diabetes duration, HbA1c, body mass index, insulin treatment, number of anti-hypertensives, history of peripheral vascular disease, and baseline eGFR (R20.87), baseline foot insensitivity was associated with study-end eGFR (B = -3.551, p = 0.036).
  
  
  CONCLUSIONS
  Patients with Type 2 diabetes and foot insensitivity are at increased risk of eGFR decline. Identifying these patients offers an opportunity to intensify metabolic and blood pressure control to prevent/retard the development of CKD. Future studies of larger sample size and longer follow up from multiple centres are needed to assess the diagnostic performance of our findings in predicting CKD development, and to compare the performance of the monofilament test with albuminuria.
authors.affiliation: Department of Diabetes and Endocrinology, Heart of England NHS Foundation Trust, Birmingham, UK.
authors.forename: Quratul A
authors.initials: QA
authors.lastname: Altaf
authors.affiliation: Department of Diabetes and Endocrinology, Heart of England NHS Foundation Trust, Birmingham, UK.
authors.forename: Hamed
authors.initials: H
authors.lastname: Sadiqi
authors.affiliation: Derby Teaching Hospitals NHS Foundation Trust, Derby, UK.|Warwick Medical School, University of Warwick, Coventry, UK.
authors.forename: Milan K
authors.initials: MK
authors.lastname: Piya
authors.affiliation: Department of Diabetes and Endocrinology, Heart of England NHS Foundation Trust, Birmingham, UK. Abd.tahrani@nhs.net.|Institute of Metabolism and Systems, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, UK. Abd.tahrani@nhs.net.|Centre of Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, B15 2TT, UK. Abd.tahrani@nhs.net.
authors.forename: Abd A
authors.initials: AA
authors.lastname: Tahrani
mesh_terms: D000328:Adult; D000368:Aged; D000419:Albuminuria / Q000150:complications / Q000175:diagnosis; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D017719:Diabetic Foot / Q000150:complications*; D003929:Diabetic Neuropathies / Q000150:complications* / Q000503:physiopathology; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D051436:Renal Insufficiency, Chronic / Q000150:complications* / Q000503:physiopathology; D012307:Risk Factors
keywords: 10 g monofilament; Albuminuria; Chronic kidney disease; Diabetic nephropathy; Diabetic neuropathy; Estimated glomerular filtration rate; Foot insensitivity