Tubular damage may play major role in development of nephropathy in pre-diabetes. Newer markers like urine NGAL and Cystatin C are raised early in diabetes and pre-diabetes nephropathy.

Frantic efforts have been made up to this date to derive consensus for estimating renal function in critically ill patients, only to open the Pandora's box. This article tries to explore the various methods available to date, the newer concepts, and the uncared issues that may still prove to be useful in estimating renal function in intensive care unit patients. The concept of augmented renal clearance, which is frequently encountered in critically ill patients, should always be taken into account, as correct therapeutic dosage of drugs sounds vital which in turn depends on correctly calculated glomerular filtration rate. Serum creatinine and creatinine-based formulae have their own demerits that are well known and established. While Cockcroft-Gault and 4-variable modification of diet in renal diseases formulae are highly inadequate in the intensive care setup for estimating glomerular filtration rate, employing isotopic methods is impractical and cumbersome. The 6-variable modification of diet in renal diseases formula fairs better as it takes into account the serum albumin and blood urea nitrogen, too. Jelliffe's and modified Jelliffe's equations take into account the rate of creatinine production and volume of distribution which in turn fluctuates heavily in a critically ill patient. Twenty-four-hour and timed creatinine clearances offer values close to reality although not accurate and cannot provide immediate results. Cystatin C is a novel agent that offers a sure promise as it is least influenced by factors that affect serum creatinine to a major extent. Aminoglycoside clearance, although still in the dark area, may prove a simple yet precise way of estimating glomerular filtration rate in those patients in whom these drugs are therapeutically employed. Optic ratiometric method has emerged as the most sophisticated one in glomerular filtration rate estimation in critically ill patients.

Chronic kidney disease (CKD) has attained epidemic proportions in India due to increased incidence of diabetes and hypertension (HTN). It was surmised that identification of only high-risk groups (HRGs) through a questionnaire would be sufficient to identify cases of kidney damage (KD). The study attempted to device a questionnaire to classify the subjects in to HRG and low-risk group (LRG) and assess the extent of early KD. The central government employees were classified into HRG and LRG based on "SCreening for Occult REnal Disease (SCORED)" and "EXTENDED" questionnaire formulated after addition of 10 more parameters apart from diabetes and HTN. Urine examination by dipstick, quantitative microalbumin, serum creatinine, and estimated glomerular filtration rate were assessed to determine KD. The data were analyzed for risk-group classification. Sensitivity was calculated based on the number of KD cases in the HRG. Of the 1104 employees screened, 58% and 42% were classified in HRG and LRG, respectively. There were 306 KD cases of whom, 65% were in the HRG. The sensitivity of the EXTENDED questionnaire to detect CKD was much higher (60%) compared to the SCORED questionnaire (25%). The prevalence of KD according to stage was: stage-1, 13.4%; stage-2, 9.9%; and late stages (3, 4, and 5), 4.5%. Microalbuminuria and dipstick-positive proteinuria showed statistically higher proportion in the HRG (25% and 4.1%) than in the LRG (19% and 1%, respectively) (P <0.05). Although the EXTENDED questionnaire was more sensitive in detecting KD, only screening the high-risk population will leave behind 35% of KD cases. There is, therefore, a need for mass screening at regular intervals.