Chlinical significance of identifying the crystals of calcium oxalate in urine has been demonstrated in many previous studies. The presence of such crystals is markedly regulated by lifestyle and habitat of an individual also. The present article is an effort to compare this aspect of health parameter (i.e. measurement of calcium oxalate crystals in routine examination of urine) between two different population groups and correlate the indicator with their customary food habit.Introduction
Crystals are formed when a crystalline compound becomes supersaturated. In urine inorganic salts such as oxalate and phosphate and oxalate salts such as uric acid and cystine may precipitate and appear in urine as true crystals or as amorphous material. Crystal formation is enhanced when urine flow through renal tubules decrease along with pH changes in the ultra filtrate 1. Crystals normally found in urine are urates, uric acid or calcium oxalates 2. The presence of these crystals is not related to pathology but they must be properly identified and reported because occasionally they may have clinical significance. For example, calcium oxalate has been considered to be one of the normal crystals as oxalates are natural end products of metabolism in the body and it is excreted out in urine. Now, if oxalate levels are too high, the extra oxalate can combine with calcium to form kidney stones and hence on several occasions it has been linked to lithiasis. Calcium oxalate crystals (COC) are the most common cause of Kidney stones and calcium oxalate (CaOx) is the most prevalent type of kidney stone which accounts for 70-80 % of the kidney stones in the population 3. The amount of oxalate excreted in urine is a major risk factor for CaOx stones formation. Another risk factor for CaOx stone is hyperoxaluria which occurs due to bowel disease (enteric hyperoxaluria) and genetic disorders of oxalate metabolism (primary hyperoxaluria) 4. Hence in cases of dietary excess of oxalate one possible approach to prevent renal stone formation and recurrence is to decrease the consumption of oxalate rich foods (ideal daily intake
should be 50 mg or less) such as tomatoes, spinach, rhubarb, garlic, oranges and asparagus 5.
Material and Method A retrospective comparative study of COC in reports of urinalysis was made between two different population groups in Tripura from the laboratory records available in the Regional Research Institute for Homoeopathy - peripheral wing of Central Council for Research in Homeopathy, New Delhi. Urinalysis comprises of physical examination, bio-chemical examination and microscopic examination. In microscopic examination the major concern are the cells (pus cells, epithelial cells and red blood cells), casts, crystals and microorganisms 2. Initially, the unit was located somewhere in the midst of the capital city, Agartala. The majority of the patients who were coming to our OPD were non-tribals. Later on, in February 2017 when the centre was upgraded to Regional research unit, it was shifted to a rural tribal area named Khumulwng. Now, the patients coming in the new OPD were primarily tribal peoples. Hence, the exposure to these two different population groups was not an experimental intervention but purely a matter of coincidence. Utilizing this opportunity for having coverage to a new and fresh population group a retrospective analysis of the reports for urine analysis was made. Reports from February 2016 to January 2018 were taken into account. Out of which the reports of 2016-17 was belonging to the urban population group in Agartala and reports of 2017-18 was belonging to the rural population group in Khumulwng.
Calcium oxalate crystals, Kidney stone, Tribal population, Araceae
Broc DA and Hundley JM. Identifying calcium oxalate crystals in Urine. Volume 26, no 11. November 1995. Available from https://academic.oup.com/labmed/article-abstruct [last cited on 20.07.18]
Sood R. Medical Laboratory technology – methods and interpretations. 5th edition. Jaypee brothers medical publishers (P) ltd. 2006: 63
Asplin JR. Hyperoxaluric calcium nephrolithiasis. Endocrinology Metabolic Clinical North American 2002; 31: 927-949
Bhasin B, Ürekli HM, and Mohamed G Atta. Primary and secondary hyperoxaluria: Understanding the enigma. World Journal of Nephrology. 6.5.2015; 4(2): 235–244
Suzanne F and Watson S. What You Need To Know About Calcium Oxalate Crystals. Available from https://www.healthline.com/health/calciumoxalate-crystals_treatment [last cited on 20.07.18]
Deb D, Sarkar A, Debbarma B, Datta BK and Majumdar K. Wild edible plants and their utilization in traditional recipes of Tripura, Northeast India. Advances in Biological research 7 (5): 203-211, 2013.
Sk. Md. A.I. Saadi and Mondal AK. Studies on the Calcium Oxalate Crystals of Some Selected Aroids (Araceae) in Eastern India. Advances In Bioresearch, Vol. 2  June 2011: 134 - 143
Tripura: Food habit. Available from http://tripuratourism.gov.in/food [last cited on 20.07.18]
Mohana Devi S, Balachandar V, Lee S and Kim H. An Outline of Meat Consumption in the Indian Population - A Pilot Review. Korean Journal for Food Science Animal Resource. 2014; 34(4): 507– 515.
Curhan GC, Willett WC, Speizer FE et al. twentyfour-hour urine chemistries and the risk of kidney stones among women and men. Kidney International 2001; 59: 2290-2298
Antonio Nouvenne, Andrea Ticinesi, llaria Morelli, Loredana Guida, Loris Borghi, and Tiziana Meschi. Fad diets and their effect on urinary stone formation. Translation andrology and urology. 2014 Sep; 3(3): 303-312
Moe OW. Kidney stones: pathophysiology and medical management. Lancet 2006 ;367: 333–44
Stamatelou KK, Francis ME, Jones CA, et al. Time trends in reported prevalence of kidney stones in the United States: 1976–1994. Kidney International 2003; 63: 1817–23
Fazil Marickar YM, Lekshmi PR, Varma L and Koshy P. Elemental distribution analysis of urinary crystals. October 2009, Volume 37, Issue 5, pp 277–282. Available from https://link.springer.com [last cited on 20.07.18]