Chronic dehydration and symptomatic upper urinary tract stones in young adults in Ibadan, Nigeria

Association between intelectin-1 variation and human kidney stone disease in northeastern Thai population

An interplay of multiple genetic and environmental factors implicates an incidence of human kidney stone disease (KSD). However, the genetic factors associated with KSD are not completely known or understood. To identify KSD-associated genetic variations among the northeastern Thai patients, a genome-wide association study (GWAS) was conducted. We initially employed genotyping of single nucleotide polymorphism (SNP) using Genome-Wide Human SNP Array 6.0 in 105 patients and in 105 normal control subjects. To overcome the limitation of small sample size, we set forth to analyze SNPs as clusters based on the concept of linkage disequilibrium (LD) and haplotype. Using this analysis, 29 genes were identified. Three candidate SNPs, including rs2039415, rs2274907, and rs3747515, were selected on the basis of haplotype analysis, potentially functional SNPs, and the functions of associated genes. Further genotyping of these SNPs in a larger sample size (altogether 216 patients and 216 control subjects) showed that the candidate SNP rs2274907 remained significantly different between case and control subjects in both genotype frequencies (OR 2.44, 95% CI 1.38-4.30; p = 0.0015) and allele frequencies (OR 1.54, 95% CI 1.17-2.03; p = 0.0021). The non-synonymous SNP rs2274907 (c.326T > A) located in exon 4 of the ITLN1 gene results in a substitution of valine (V) by aspartate (D) at position 109 (p.V109D). This substitution could affect the predicted hydrogen (H)-bonds between lysine (K) 107 and glutamine (Q) 104, which supports its association with KSD in this population.

Sonographic assessment of urolithiasis in University of Abuja Teaching Hospital, Nigeria

Background:

Urolithiasis may result in many complications including renal failure. There is a paucity of documented scientific study on the prevalence of urolithiasis in the University of Abuja Teaching Hospital within the Federal Capital Territory, Nigeria. The aim of the study was to assess the prevalence of urolithiasis in patients undergoing ultrasound at University of Abuja Teaching Hospital.

Materials and Methods:

This study which adopted a survey approach was conducted at the Department of Radiology, University of Abuja Teaching Hospital between June 2014 and May 2015. A total of 2310 patients that underwent abdominopelvic ultrasound in the department who aged between 2 and 64 years and met the inclusion criteria participated in the study. They were recruited using a convenience (nonprobability) sampling technique. Data obtained were subjected to descriptive statistics and analyzed using Student's t-test. P < 0.05 was considered statistically significant.

Results:

A total of 2310 patients were scanned, 31 patients were sonographically identified with urolithiasis. The prevalence of urolithiasis was 13.4/1000. The mean age was 31.12 ± 3.69 years. There were 58.06% males and 41.93% females giving a male-to-female ratio of 1.3:1. The peak age of incidence was 21–50 years. Majority (22 [71%]) were located in the upper urinary tract, whereas 9 (27%) were in the lower urinary tract. The most common presenting symptoms were flank/loin pains (renal colic) noted in 12 (40%) patients, followed by hematuria in 4 (13.3%) patients.

Conclusion:

The prevalence of urolithiasis was 13.4/1000. This information can be utilized in formulating future health plans for prevention of urolithiasis in the hospitals within this locality.

The Myth of Water and Salt: From Aquaretics to Tenapanor

The impact of water intake has been studied in several renal diseases. For example, increasing water intake is useful to prevent primary and secondary nephrolithiasis. In autosomal dominant polycystic kidney disease, arginine vasopressin (AVP) is involved in the progression of the disease, and water intake could play a therapeutic role by inhibiting the synthesis of AVP, but its efficacy is still controversial. Conversely, the use of aquaretics, which are antagonists of AVP V2 receptors, results in the reduction of the increase rate of total kidney volume with a slower decline of glomerular filtration rate. In chronic kidney disease, AVP contributes to glomerular hyperfiltration, arterial hypertension, and synthesis of renin, resulting in renal sclerosis. Increased water intake could reduce AVP activation determining a potential protective effect on the kidney, but its efficacy has not yet been clearly demonstrated. On the other side, sodium and potassium play an important role in the control of arterial blood pressure and are involved in the development and progression of chronic kidney disease. Reduction of sodium intake and increase of potassium intake determine a decrease of arterial blood pressure with a beneficial effect on the kidney; however, adherence to sodium restriction is very poor. Regarding this, sodium-hydrogen exchanger isoform 3 inhibitors may reduce sodium absorption in the gut. The most recent sodium-hydrogen exchanger isoform 3 inhibitor, known as tenapanor, reduces extracellular fluid volume, left ventricular hypertrophy, albuminuria, and blood pressure in experimental studies and increases fecal loss of sodium in humans.