Gout and diabetes: a common combination

Introduction

Gout is a common, painful but potentially treatable inflammatory arthritis characterised by acute recurrent deposition of monosodium urate crystals in affected joints, periarticular and subcutaneous tissues with the subsequent development of tophi. 1 2 The single most important risk factor for the development of gout is a raised level of uric acid in the extracellular fluid resulting in the precipitation of urate crystals. 3 There are strong cross-sectional associations between hyperuricaemia, gout and the components of the metabolic syndrome (MetS). 4-6 In addition, hyperuricaemia leads to the deposition of urate crystals in the renal tract and appears to be an independent risk factor for chronic kidney disease (CKD) and cardiovascular events, particularly in patients with type 2 diabetes mellitus (T2DM). 7 8

The reported prevalence in the UK is approximately 2.5%. 9 In several studies T2DM has been reported to be associated with an increased risk of gout. 10-13 Other important risk factors include increasing age, male gender, obesity, alcohol intake and various medications. 14 The aims of this cross-sectional study were to compare the prevalence of gout in people with either type 1 diabetes mellitus (T1DM) or T2DM with those people without diabetes mellitus. We also compared those with both conditions to those with gout only and T2DM only with respect to age, gender, smoking status, number and type of prescribed medications, urate level, glycaemic control, blood pressure (BP), body mass index (BMI), lipids, renal function, haemoglobin and diabetes complications. We have also attempted to create a model for predicting gout in people with T2DM.

Methods

Fifty of the 51 General Practices using Egton Medical Information System (EMIS) in NHS Ayrshire and Arran (population 340 377) contributed data from their practice computer systems. Patients with gout were identified if they had a recorded diagnosis (using Read codes (v2)) and/or whether the patient had been prescribed a gout treatment (allopurinol, probenecid, colchicine, sulfinpyrazone or febuxostat). Other data collected included were a diagnosis of diabetes mellitus (by type), BMI, haemoglobin A1c (HbA_1c ), smoking status, lipid levels, and the use of lipid-lowering therapy and antihypertensive medications, alongside complications including ischaemic heart disease, cerebrovascular disease, diabetic foot ulcers, retinopathy and neuropathy. Raised BMI, raised total cholesterol, reduced high-density lipoprotein (HDL)-cholesterol and raised non-fasting triglycerides...