| Abstract | Šećerna bolest je kronični metabolički sindrom nastao zbog apsolutnog i/ili relativnog manjka inzulina, a karakteriziran je kroničnom hiperglikemijom koju prate poremećaji u metabolizmu ugljikohidrata, masti i proteina. Koncentracija glukoze mora se održavati unutar određenih granica kako se ne bi razvile akutne i kronične komplikacije šećerne bolesti. Glikacijom odnosno neenzimskim kovalentnim vezanjem glukoze za amino skupinu proteina nastaju hemoglobin A1c i glikirani albumin. HbA1c je „zlatni standard“ za kliničko praćenje šećerne bolesti i odražava stanje glikemijske kontrole unatrag 2-3 mjeseca. Glikirani albumin odražava stanje glikemijske kontrole unatrag 2-3 tjedna te je pogodan za praćenje glikemije u pacijenata kod kojih koncentracija glukoze u krvi varira tokom određenog kratkog perioda. U nekih bolesti i stanja kao što su kronična bolest bubrega, anemija i primjena hemodijalize, glikirani albumin je bolji biomarker kontrole šećerne bolesti od HbA1c koji u tim slučajevima ne daje pouzdane rezultate. HbA1c, glikirani albumin i koncentracija glukoze određuju se iz uzorka krvi, a uzorkovanje krvi je invazivan postupak koji u pacijenata sa šećernom bolesti koji glikemiju moraju kontrolirati na dnevnoj bazi, izaziva bol i neugodu. Razvijaju se i istražuju neinvazivne metode praćenja koncentracije glukoze. Osim u krvi, glukoza se može naći u različitim tjelesnim tekućinama kao što su intersticijska tekućina, suze, slina, urin i znoj. Glikirani albumin osim u krvi može se određivati u suzama kao neivazivna metoda za praćenje šećerne bolesti. Suze su kompleksna biološka tekućina i sadržavaju elektrolite, proteine, lipide, mucine, glukozu i neke male organske molekule i metabolite. U sadržaju suza mogu se naći ioni natrija, kalija, magnezija, kalcija, klorida, bikarbonata i fosfata. Najznačajniji proteini su lizozim, laktoferin, sekretorni imunoglobulin A, serumski albumin, lipokalin-1 i lipofilin. Suze se mogu sakupljati na nekoliko načina, a različiti načini uzorkovanja utječu na kvalitetu uzorka suza te posljedično na rezultat analize proteina u suzama. U suzama je moguće odrediti brojne analite što uz standardne pretrage i biomarkere može pridonijeti dijagnostici, probiru i praćenju različitih bolesti oka te sistemskih bolesti. |
| Abstract (english) | Diabetes mellitus is a chronic metabolic syndrome caused by absolute and /or relative lack of insulin, and is characterized by chronic hyperglycemia accompanied by disorders in metabolism of carbohydrates, fats and proteins. Glucose concentration must be maintained within certain limits to avoid the development of acute and chronic complications of diabetes. Hemoglobin A1c and glycated albumin are formed by glycation or non-enzymatic covalent binding of glucose to the amino group of proteins. HbA1c is the "gold standard" for clinical monitoring of diabetes and reflects the state of glycemic control in the previous 2 to 3 months. Glycated albumin reflects the state of glycemic control in the previous 2 to 3 weeks and is suitable for monitoring glycemia in patients in whom blood glucose levels vary over a period of time. In some diseases and conditions such as chronic kidney disease, anemia and use of hemodialysis, glycated albumin is a better biomarker of diabetes control than HbA1c which, in these cases, does not give reliable results. HbA1c, glycated albumin, and glucose concentration are determined from a blood sample, and blood sampling is an invasive procedure that causes pain and discomfort in diabetic patients who must control glycemia on a daily basis. Non-invasive methods for monitoring glucose concentration are being developed and investigated. In addition to blood, glucose can be found in various body fluids such as interstitial fluid, tears, saliva, urine and sweat. Glycated albumin, other than in blood, can be determined in tears as a non-invasive method of monitoring diabetes. Tears are complex biological fluids and contain electrolytes, proteins, lipids, mucins, glucose, and some small organic molecules and metabolites. Sodium, potassium, magnesium, calcium, chloride, bicarbonate and phosphate ions can be found as the contents of tears. The most important proteins are lysozyme, lactoferrin, secretory immunoglobulin A, serum albumin, lipocalin-1 and lipophilin. Tears can be collected in several ways, and different sampling methods affect the quality of tear sample and consequently the result of protein analysis in the tears. The fact that it is possible to determine a lot of analytes in tears, combined with standard tests and biomarkers, can contribute to diagnosis, screening and monitoring of various eye diseases and systemic diseases. |
