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EDITORIALS: Daniel E Weiner and Dena E Rifkin Kidney function and the risk of cardiovascular disease BMJ 2009; 338: b1307 [Full text]

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Pulse Mass Index, Kidney function and the risk of cardiovascular disease

Prof. Enrique J. Sanchez-Delgado, MD   (6 July 2009)

Pulse Mass Index, Kidney function and the risk of cardiovascular disease 6 July 2009
Prof. Enrique J. Sanchez-Delgado, MD, Internist-Clinical Pharmacologist, Director of Medical Education Hospital Metropolitano Vivan Pellas, Managua, Nicaragua Send response to journal: Re: Pulse Mass Index, Kidney function and the risk of cardiovascular disease	Pulse Mass Index, Kidney function and the risk of cardiovascular disease The reciprocal of serum creatinine (1/SCr) is frequently used as a simple but inaccurate estimated glomerular filtration rate (eGFR). I proposed years ago to investigate the possible usefulness and accuracy of 1/SCr divided by the PULSE by MASS INDEX or PMI (1) (see my response to Rule et. al., Ann. Intern. Med., Dec.21, 2004). For example, for a normal SCr of 1.1 mg/dl and a normal PMI of 1.0, the eGFR would be 0.9 or 90% of normal. For a SCr of 1.5, it would be 0.66. If the Pulse Mass Index (PMI) was 1.3, which is common in patients with a high global cardiovascular risk according to the Framingham Risk Equation, the eGFR would be 0.7 (70 % of normal) in the case of 1.1 mg SCr or 0.51 (less than 60 % of normal) for a SCr of 1.5 mg. The higher the PMI, the lower the expected eGFR for a given value of SCr. Using one of the original examples from Rule, if a 50-year-old woman presented to donate a kidney and had a Mayo Clinic serum creatinine of 1.1 mg/dL , she would have an eGFR of 90 mL/min per 1.73 m2. If this woman had a BMI of 27 (69 kg, 1.6m), and a RHR of 80, her PMI would be 1.25 and her eGFR 0.73 (73% of normal). This eGFR is normal, but less than ideal, reflecting her higher cardiovascular risk. The PULSExMASS INDEX (PMI) is calculated as follows: Body Mass Index (BMI) multiplied by Resting Heart Rate (RHR) and divided by 1730 (24x72). The PMI considers the weigh in kilograms, the high in meters (BMI =Kg/m2) and the RHR. The normal values of BMI (average 24) are similar in males and females. The RHR (average 72) reflects the basal metabolic rate and related factors, both in healthy, fit as in sick people. The Pulse Mass Index reflects all these elements and correlates highly both with the body surface area, and the global cardiovascular risk (known to be elevated in renal patients), being much easier to calculate. If 1/SCr/PMI resulted to be acceptably accurate to estimate the GFR, it would facilitate the daily work with renal patients, until we know more from cystatin C. Prof. Enrique Sánchez-Delgado MD Internist-Clinical Pharmacologist Director of Medical Education Hospital Metropolitano Vivian Pellas, Managua, Nicaragua References 1.Gilbert Ross, Jeff Stier, Donald M Lloyd-Jones, Daniel Levy, Enrique Sánchez-Delgado, et al. Lifetime risk of developing coronary heart disease. Lancet 1999 (13 March); 353:924-925 Competing interests: None declared