1. ¹Cardiovascular Division, Toujinkai Hospital, Kyoto, Japan
2. ²Division of Gastroenterology, Toujinkai Hospital, Kyoto, Japan
3. ³Division of Urology, Toujinkai Hospital, Kyoto, Japan
4. ⁴Division of Orthopedics, Toujinkai Hospital, Kyoto, Japan
5. ⁵Division of Surgery, Toujinkai Hospital, Kyoto, Japan
6. ⁶Department of Interventional Cardiology, Second Kyoto Red Cross Hospital, Kyoto, Japan
7. ⁷Department of Clinical Sciences and Laboratory Medicine, Kansai Medical University, Moriguchi, Japan

Correspondence: M Nishimura, Cardiovascular Division, Toujinkai Hospital, 83-1, Iga, Momoyama-cho, Fushimi-ku, Kyoto 612-8026, Japan. E-mail: mnishimura@tea.ocn.ne.jp

Received 7 August 2005; Revised 22 September 2005; Accepted 5 October 2005; Published online 4 January 2006.

Abstract

We investigated whether insulin resistance is associated with impaired cardiac fatty acid metabolism in maintenance hemodialysis patients without coronary artery disease. We studied 55 nondiabetic (6311 years old) and 51 diabetic (6110 years old) hemodialysis patients with normal coronary arteries, using single-photon emission computed tomography (SPECT) with an iodinated fatty acid analogue, iodine-123--methyl iodophenyl-pentadecanoic acid (¹²³I-BMIPP), to evaluate cardiac fatty acid metabolism. SPECT imaging was graded regionally from 0 (normal) to 4 (absence of tracer) to calculate a summed score for 17 left ventricular segments. Insulin resistance was determined using the homeostasis model assessment index of insulin resistance (HOMA-IR). HOMA-IR correlated with summed BMIPP score in nondiabetic and diabetic patients. Stepwise multiple regression analysis showed that HOMA-IR was independently associated with BMIPP summed score in nondiabetic (=0.774, t=9.218, P=0.0001) and diabetic patients (=0.792, t=9.079, P=0.0001). Left ventricular ejection fraction was lower in nondiabetic subjects with BMIPP summed score of at least 6 plus HOMA-IR of at least 4 than in others with lower values for both assessments (53.113.8%, n=20 vs 67.79.1%, n=23, P=0.0002); this was also true in diabetic subjects (50.915.2%, n=24 vs 71.013.6%, n=11, P=0.0007). Association between insulin resistance and impaired cardiac fatty acid metabolism may contribute to left ventricular dysfunction in patients with maintenance hemodialysis without coronary diseases.