Adipose Tissue Fatty Acid Composition, Serum Lipids, and Serum α-Tocopherol in Continuous Ambulatory Peritoneal Dialysis Patients Living on the Island of Crete

Abstract

A pilot study to explore diet-related atherogenic patterns in continuous ambulatory peritoneal dialysis (CAPD) patients on the island of Crete. Cretans are well known for their high olive consumption and low atherosclerotic heart disease mortality, in general. Case-control study. This was a hospital-based study initiated in 1991. Catchment area was the island of Crete, Greece. Seventeen patients admitted for treatment to the General State Hospital of Rethimnon. Controls were selected from the general population of the island and consisted of a random sample of 27 subjects from a total of 168 healthy subjects who visited the Preventive Medicine Clinic of the University Hospital for routine check-up. The control group was age- and sex-matched with patients. Both CAPD patients and controls had been residents of Crete for at least the last 10 years. Adipose tissue was aspirated, and a 12-hour fasting blood sample was collected for determination of serum lipid parameters and serum alpha-tocopherol levels; dietary data from a 3-day recall were recorded. No significant differences between the two groups were observed with respect to the mean macronutrient intake. The mean levels of serum triglycerides (p = 0.016) and serum alpha-tocopherol (p = 0.001) were significantly higher in CAPD patients compared to controls. Mean levels of total serum cholesterol, high density lipoprotein (HDL) cholesterol, and low density lipoprotein (LDL) cholesterol were not significantly different. In CAPD patients the mean total percentage of monounsaturated fatty acids (MUFA) was significantly higher (p = 0.006) than in controls. The mean total percentage of saturated fatty acids (p = 0.004), along with the mean percentage of omega-6 (p = 0.002), the mean value of the ratio omega-6/omega-3 (p < 0.0001), and the percentage of linoleic acid (p = 0.001) were significantly lower in CAPD patients than in the controls. Among subjects with higher levels of MUFA in the adipose tissue, the CAPD patients were twice as likely to have high serum alpha-tocopherol (p < 0.001), and 2.6 times more likely to be in high risk of high total cholesterol (TC)/HDL (p = 0.08) compared to the controls. However, CAPD patients with high levels of MUFA in the adipose tissue (above the average of 65%) were unlikely [odds ratio (OR) = 0.001, p < 0.001] to be at risk of high TC/HDL (above the average of 4.1), and maybe unlikely (OR = 0.08, but p = 0.1) to have low serum alpha-tocopherol, when compared with the CAPD patients with low levels of MUFA. CAPD patients with high TC/HDL are 0.15 times less likely (p = 0.1) to have high levels of serum alpha-tocopherol compared to those with low TC/HDL. Cretan CAPD patients demonstrate an interesting profile consisting of unexpectedly positive aspects when atherogenesis-related factors such as those of adipose tissue fatty acid composition, serum lipids, and serum antioxidant alpha-tocopherol are considered.