Introduction:
Over the last few years, the prevalence of obesity has increased dramatically, not only in the western world but also in LMICs like India. Obesity increases the risk for a number of health conditions including hypertension, diabetes and chronic kidney disease (CKD) Obese individuals have a significantly markedly higher risk of developing kidney disease and progressing end-stage kidney disease. Obesity-related kidney involvement includes proteinuria and histopathological examination reveals glomerulomegaly and foot process effacement (secondary focal segmental glomerulosclerosis). This leads to progressive kidney damage in individuals with higher body mass index (BMI). There are not many studies looking into the impact of increasing body mass index on glomerular filtration.
However, assessment of Glomerular Filtration Rate (GFR) is required as it is considered the best single metric for assessment of renal function. GFR can be estimated either using measured clearance of various glomerular filtered agents in research setting or can be assessed by mathematical calculations (estimated GFR) and using nuclear scans (measured GFR).
Methods:
Prospective study involving 82 individuals who were relatively healthy and who were seen in our hospital were included. Their BMI was noted and their GFR was estimated using CKD-EPI equation. After informed consent, 99m Tc DTPA renograms were acquired by dynamic acquisition to calculate their measured GFR.GFR was calculated by Gates renal processing with the separate depth correction estimations using various automated depth corrections methods (Itoh and Emory). GFR was reported as ml/min. The demographic variables (age, gender, height weight and BMI) were measured. Serum creatinine was measured in all patients. Individuals with diabetes mellitus and renal failure were excluded from the study. The BMI of these subjects were divided into four categories (<20, 20-25, 26-30 and>30). The eGFR and mGFR were noted in each BMI category and data was analysed to see if there were any impact of BMI on GFR in relatively healthy individuals. All statistical analysis was done using SPSS Version 24.
Results:
A total of 82 patients were studied prospectively from 15th January 2024 till 15th July 2024. The number of males in this group was 63. The mean(sd) age of the cohort was 45.5(16.1) years. The mean(±sd) weight of the cohort was 67.5 (±16.2) kgs.The mean (±sd) BMI was 25.26(±4.94). The mean(±sd) creatinine was.063(±0.34) mg/dl. All individuals studied had normal creatinine based on laboratory examination. None had type 2 diabetes mellitus and only 3 individuals had hypertension which was well controlled with a single anti-hypertensive. Both eGFR (CKD -EPI) and GFR measured with nuclear medicine scans showed a negative correlation with BMI. With rising BMI, the GFR in individuals progressively declined. In individuals with BMI< 20, the mean (sd) eGFR (CKD -EPI) was 115.98 (40.89) ml/min, whereas it was 94.81(31.33) ml/min in individuals with BMI> 30 (p=0.033). GFR measured with nuclear scans also showed similar trend but the decline was not significant.
Conclusions:
In individuals with no major comorbidities, increasing BMI is associated with declining eGFR. The findings in this small study needs to be corroborated with more robust evidence.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.