Relations between chemical composition of urinary sediment and dietary habits

Justina Aleksaitė1, Vaiva Hendrixson2, Jonas Algis Abaravičius2

1 Republican Vilnius University hospital

2 Vilnius University


Introduction: urinary stone disease is common worldwide, with a prevalence of about 10 % of the human population. One of the key conditions for urolithiasis to occur is urine oversaturation with some specific chemical components, which can be caused by inadequate diet and inflammatory processes. It is only possible to begin early and efficient treatment, prevention and diet recommendations to patients when the composition of kidney stones is known. Using Fourier infrared microspectrometry to test the chemical composition of urinary sediments provides a very accurate evaluation of the origin of stones. Examining the chemical composition of urinary sediments before the formation of stones would enable doctors to predict and avoid recurrences of common urinary tract stones. The relationship between the chemical composition of urinary sediments and nutritional habits aims to improve disease prevention and to better understand the mechanisms of the formation of kidney stones.

Aim: to analyze the relationship between the dietary habits and body mass index of healthy volunteers and the chemical composition of urinary sediments. Materials and Methods: 136 healthy volunteers (105 women and 31 men) participated in the study. Body mass index was evaluated.
A food frequency questionnaire was used to evaluate their eating habits. Particular attention was taken to the frequent consumption (> 2 times per week) of dairy products, meat, fish, oxalate rich foods (beets, rhubarb, chocolate, nuts, tea, berries) and alcohol. Urine samples of the volunteers were taken and the urinary sediments were examined using Fourier infrared microspectroscopy. Results: the average age of the volunteers was 44 years. The main types of urinary sediments investigated using infrared microspectroscopy were: struvite 44.12%; uric acid 26.47% and calcium oxalate 10.29%. No sediments – 19.12% of samples. According to body mass index subjects distributed: lower than normal – 3.68%; normal – 45.59%; overweight or obese – 50.74%. Analysis of the relationship between the dietary habits and chemical composition of volunteers urinary sediments showed that the consumption of alcohol had a significant impact uric acid sediments (p=0.01) but not on struvite or calcium oxalate. The frequent consumption of meat had an impact on calcium oxalate (p=0.003) and struvite (p=0.014), but not on uric acid sediments. A diet rich in oxalates had a significant impact on uric acid (p=0.035) and calcium oxalate (p=0.03) sediments, but not to on struvite. There was no statistically significant relationship found between the chemical composition of urinary sediments and consumption of fish or dairy products. A higher than normal body mass index (>25) has relationship with struvite sediments (p=0.012) Conclusions: a statistically significant relationship between the frequent consumption of alcohol and food rich in oxalates and urinary sediments of uric acid was found. The presence of calcium oxalate sediments in the urine of healthy volunteers was significantly related to a diet rich in meat and oxalates, whereas struvite was related to the frequent consumption of meat and high body mass index.

Keyword: Urinary sediments, Fourier infrared microspectrometry, urolithiasis, nutrition.