Homeostasis improves and maintains organism functional systems . The nervous system regulates organism homeostasis in the inward environment by answering external stimulus . The vegetative and autonomous nerve system regulate the function of the internal organs . Enable the transport of hormones, vitamins, minerals and metabolism products through the Blood to distant tissues and organ systems . Fluid in the inner environment contains nutritional material and oxygen, enabling the continuous renewal of molecules at the capillary . Body fluid consists of cellular (in cells) and extracellular (in the Blood) water . The Water amount in an organism depends on body mass, nutrition, age and gender . The cellular fluid has a changeable lining and depends on tissue and organ . Water has a protective (part of immunoglobulin, proteins) or regulator (par of hormones or enzymes) role in the body . Water is an essential molecule for all living organisms and the most common compound on earth . It is the ideal solvent and forms a useful environment for biochemical processes in a temperature range of 0-100°C . Water forms hydrogen bonds with proteins, DNA and RNA molecules . Water intake and hydration status are associated with disease prevalence, disease development and exercise performance .
The homeostatic mechanism precisely maintains Blood plasma and extracellular fluid content . The Blood regulates cardiac function, integrity and elasticity of blood vessels, communicates with cells, tissues and organs . Blood has a respiratory, nutritive, excretory, regulatory, transport and defensive role in an organism . Water is quantitatively the most significant blood constituent. Blood contains fluid (45%, plasma, serum) and constitutive (55%, shaped elements like Erythrocytes, Leucocytes, Platelets) component . The serum is plasma without fibrinogen. Plasma contains organic and inorganic matter, like water (92%), proteins (7%) and other ingredients (1-2%) . Plasma contains blood cells of whole blood, proteins (albumin, globulin and fibrinogen), glucose, clotting factors, electrolytes, hormones and carbon dioxide. The most indispensable cation ions are Na+, K+, Ca2+, Mg2+ and anion ions like Cl-, P2+, P03-, S04-, NaH2PO4, Na2HPO4 and microelements like Fe2+, Cu2+, Zn2+, Co2+, J-[6, 17. The most common blood salts, NaCl and NaC03, regulates osmotic pressure and chemical reactions. .
Urine is a renal product of organic and inorganic material, a bright liquid with a light yellow colour, specific smell and salt-bitter taste . The founded state of metabolism and nutrition causes changes in Urine constituent in the physiological and non-physiological range. The colour of Urine depends on constituent concentration, pigments and pathological content. Urine contains 95-97% water and 3-5% diluted material. Inorganic constituents are Na+, K+, Ca2+, Mg2+, NH4 and anion Cl-, P2+, HCO3-, SO42-. Organic components can be nitrogen and non-nitrogen . Nitrogen materials are urea, creatinine_Cr, uric acid, amino acid, while non-nitrogen materials belong to phenol, oxalate, glucuronic acid and milky acid . A small number of ferments, hormones and vitamins are present . Intercellular fluids are relatively constant fluids, while tissue fluid and blood plasma are inconstant to change . Maintaining organism homeostasis is significant for permanent composition and volume of body fluid (1). Human organism contains small water supplies. During the day, 1.5-2l of water evaporates through Urine, faeces, lung sweat and skin . Knowledge about biological and chemical processes affects establishing reference range, disease diagnosis, prognosis and follow-up.
Sustainable effort must obtain for sensitivity, specificity, robustness and reproducibility of data. Pre-analytical factors influence sample quality; reproducibility, stability and false-positive results. . Pre-analytic variables include 3. categories, physiologic (age, gender, sex, time, season, altitude, menstruation, pregnancy, lifestyle like diet, caffeine, ethanol, smoking), specimens collection (overnight fasting, time of specimen collection, posture during sampling, exercise, water intake, anticoagulants-blood ratio, specimen handling and processing, added additives with anticoagulants), and influence or interference factors (drug metabolites, laboratory tests, collection tube) affecting variable range . Information about water intake and sampling enable appropriate diagnostic and therapeutic strategy for human disease monitoring and treatment. Water intake, a pre-analytical variable, contributes to biochemical processes and affects establishing reference range, disease diagnosis, prognosis and follow-up . Studies analyzed conditions like storage time, temperature, freezing-thawing cycle on biomarker range and reproducibility . Despite increasing sensitivity of methodology for determining biomarker range, discrepancies among variables exist in the literature due to sampling frequency, sample and pre-analytical factor interaction complexity . Critical aspects of biomarker results, stability during clinical planning, sample collection, training, selection of sample preservation, buffers, shipping, logistics and method analysis is known for the most utilized bio-specimens . Urine and Blood samples are the most commonly used in clinical practice reflecting state of metabolome and metabolic end product . Few researchers correlated Urine and Blood parameters with water intake in healthy participants. The relationship between hydration, Urine/Blood biomarker and total fluid intake in pregnant and lactating women during 3 semesters is estimated . Observational studies recorded and assessed the amount of firm food/ beverage and Urine parameters (osmolarity, volume, gravity and colour) in healthy children and elderly individuals for 24h [12, 13]. A cross-sectional study on healthy Male college students in China assed hydration status, fluid intake and Urine biomarker (osmolarity, specific gravity, pH, the concentration of K+, Na+ and Cl2-) for 24 hours . Moreover, Urine hydration biomarker (P04-, Uric acid, Urea, Cr, K+, Na+, Mg2+, Ca2+) for 24 hours is analyzed . Change in Blood biomarkers (Whole Blood cells, Erythrocyte_ER, Haemoglobin_Hg, Hematocrite_Ht, Mean Corpuscular Volume_MCV, Mean Corpuscular Hemoglobin_MCH, Mean Corpuscular Hemoglobin Concentration_MCHC, Mean Platelet Volume_MPV, Trombocytes_TR) in the control_C and test_T group on 1st day and two weeks later is determine . Urea concentrations in Blood samples after freezing at -80 degrease is analyzed . Fluid intake habits and sample sampling effect on Urine and Blood biomarkers of healthy participants lack in literature. Sample sampling can lead to results bias. Protocol for sample collection frequency, handling, and storage ensure reliable analysis of disease in routine practice and clinical trials . Daily circadian rhythm influence physiological processes and diurnal dynamic . Time-of-day-dependent oscillations in Blood level molecules could be a potential cause of variability in laboratory results, making sampling time an important consideration .
Blood and Urine biomarker change during the regime of 9 consecutive days of water intake in healthy participant lack. There is a lack of literature about the effect of water intake regime and sample sampling as a pre-analytical factor influencing Blood and Urine biomarker range in healthy subjects. A current study was done as a part of the PhD thesis aim to examine the effect of 7 and 9-day regime water intake in Test (T) and Control (C) group on 7-Blood (Freezing point depression_FPD, Potassium_K+, Sodium_Na+, Chloride_Cl-, Urea, Creatinine_Cr, Urate) and 17-Urine (Urea, Cr, Urat, Glucose_Glu, C reactive protein_CRP, Leucocyte_LE, Erythrocyte_ER, Hemoglobine_Hg, Hematocrit_Ht, Mean Corpuscular Volume_MCV, Mean Corpuscular Hemoglobin_MCH, Mean Corpuscular Hemoglobin Concentration_MCHC, MPV_Mean Platelet Volume, Trombocyte_TR, K+, Na+, Cl-) parameters in healthy subjects, during 2 sample collection, depending on gender and water intake level. Hypothesis postulate that water intake affects the reference range of Urine and Blood biomarkers.