Creatinine and insulin predict cardiac mass in drug-naïve hypertensive patients

Area of Science:

• Cardiology
• Nephrology
• Endocrinology

Background:

• Blood pressure (BP) is a known determinant of hypertensive left ventricular mass (LVM), accounting for 10-25% of its variability.
• Reduced kidney function is increasingly recognized as a factor associated with increased LVM.
• Exploring additional factors beyond BP is crucial for understanding LVM development.

Purpose of the Study:

• To investigate the independent and interactive roles of fasting insulin and serum creatinine in determining LVM in untreated hypertensive patients with preserved renal function.
• To identify key predictors of left ventricular mass index (LVMI) beyond traditional risk factors.

Main Methods:

• 1000 untreated hypertensive patients with serum creatinine ≤ 1.5mg/dL and no proteinuria were enrolled.
• Left ventricular mass (LVM) was calculated using the Devereux formula and indexed by body surface area (LVMI).
• Measurements included BP, plasma glucose, serum insulin, cholesterol, triglyceride, creatinine, and estimated glomerular filtration rate (e-GFR).

Main Results:

• Univariate analysis revealed significant direct relationships between insulin (r=0.44, P<0.0001) and creatinine (r=0.37, P<0.001) with LVMI.
• Multivariate regression identified fasting insulin as the primary predictor of LVMI variability (semipartial r=0.34, P<0.001), followed by creatinine.
• A significant interaction between insulin and creatinine was observed: a 0.1mg/dL increase in creatinine was associated with an 8.1g/m(2) increase in LVMI in patients with higher insulin levels.

Conclusions:

• Fasting insulin and serum creatinine are independent contributors to LVM development in hypertensive individuals with preserved renal function.
• Insulin and creatinine interact significantly in explaining LVM variability within this patient cohort.
• These findings highlight the importance of metabolic and renal factors in hypertensive heart disease.