HYPERTENSION PHENOTYPES AND KIDNEY INJURY IN YOUNG ADULTS: AN INTERNAL MEDICINE NEPHROLOGY INTERFACE

Background: Hypertension in young adults is increasingly recognized as a precursor of chronic kidney disease, but its impact may vary depending on blood pressure phenotype. Objective: To determine the distribution of hypertension phenotypes in young adults and to evaluate their association with early indicators of kidney injury. Methods: A cross-sectional study was conducted at the Department of Nephrology, Mufti Mehmood Teaching Hospital, Dera Ismail Khan, Pakistan, from January to June 2024. Seventy-two young adults aged 18–35 years were enrolled. Demographic and clinical details were recorded, and participants were classified into normotension, isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), systolic–diastolic hypertension (SDH), masked hypertension, and white-coat hypertension. Renal function was assessed using serum creatinine, estimated glomerular filtration rate (eGFR), and urine albumin-to-creatinine ratio (UACR). Kidney injury was defined as microalbuminuria (UACR ≥ 30 mg/g) or eGFR < 90 ml/min/1.73m². Results: SDH was the most common phenotype (31.9%), followed by IDH (19.4%) and ISH (16.7%). SDH was strongly associated with kidney injury, with 52.2% of affected individuals showing either microalbuminuria or reduced eGFR (p = 0.004). Normotensive participants had preserved renal function, while masked and white-coat hypertension showed intermediate risk. Conclusion: Hypertension phenotypes in young adults differ in their renal implications, with SDH carrying the highest risk for early kidney injury. Phenotype-specific risk stratification and timely renal monitoring may help reduce the long-term burden of chronic kidney disease in this population.