Determinants of Crystalluria among Type 2 Diabetes Patients; A Case-Control Study of the Agona West Municipality, Ghana.

Background/Aim: Type 2 diabetes mellitus (T2DM) has been implicated as a risk factor for nephrolithiasis. The aim of this study was to determine the prevalence and types of crystalluria among individuals with T2DM. It further sought to identify associated risks, which could influence crystalluria.

Methods: A case-control study with random sampling of 165 diabetes patients (cases) and 40 healthy non-diabetics (controls) was conducted from December 2012 to May 2013 at the Agona Swedru Municipal Hospital, Ghana. Sociodemographic and anthropometric data were obtained from the participants. Blood and urine samples were collected for the estimation of blood glucose (fasting) and urinalysis for the presence of crystals, respectively (light microscopy).

Results: Overall frequency of crystalluria was 18.0%. The prevalence of urine crystals in diabetics (17.5%) was more than that in non-diabetics (5.0%). Types of crystals found in the T2DM patients by prevalence were calcium oxalate (12.7%), uric acid (3.6%), and tyrosine (1.2%). Mean age, body mass index, systolic blood pressure, and fasting blood glucose (FBG) were higher among case participants than in controls ( P < 0.001; P < 0.001; P = 0.018; P < 0.001). Case participants had a lower urine pH than the controls ( P < 0.001). Crystalluria was positively correlated with FBG ( P = 0.002) and negatively with urine pH ( P = 0.108). On multivariate analysis, FBG was independently associated with crystalluria ( P = 0.002), after adjustment for other factors.

Conclusion: Crystalluria is common in diabetes patients. Acidic urine pH is mostly seen in T2DM and may be a predisposing factor to crystalluria. Good glycemic control may be a helpful in reducing the occurrence of crystalluria among T2DM.