Supportive Effects of Online Hemodiafiltration Therapy on the Nutritional State and Lipid Profile in Very Elderly Dialysis Patients

<b><i>Introduction:</i></b> Online hemodiafiltration (HDF) therapy has been recognized as one of the potential dialysis modalities. However, the long-term effects of online HDF therapy on very elderly dialysis patients older than 75 years have yet to be fully elucidated. <b><i>Methods:</i></b> Seventy-four very elderly patients older than 75 years undergoing maintenance dialysis therapy were studied retrospectively. Twenty-four (mean ± SE, 81.5 ± 1.0 years) were treated by predilution online HDF, and fifty (81.2 ± 0.6 years) were treated by conventional hemodialysis (HD) for 3 years. Laboratory data related to the nutritional state and lipid profile were collected. Body composition was measured by a bioelectrical impedance method. <b><i>Results:</i></b> Dry weight and body mass index decreased in HD patients (2.9%, <i>p</i> = 0.003 and 3.1%, <i>p</i> = 0.001, respectively), while no significant changes were found in online HDF patients. Serum albumin levels reduced in both HD and online HDF groups (3.5%, <i>p</i> = 0.003 and 2.9%, <i>p</i> = 0.026, respectively). The geriatric nutritional risk index decreased in HD patients (3.0%, <i>p</i> &#x3c; 0.001), while no significant change was shown in online HDF patients. Body composition analysis demonstrated a significant decrease in intracellular water and increases in extracellular water and edema ratio in both groups. Fat mass and %fat showed significant decreases in HD patients (8.1%, <i>p</i> = 0.003 and 7.3%, <i>p</i> = 0.003, respectively), but no significant changes in online HDF patients. Among laboratory data, serum high-density lipoprotein cholesterol levels did not change in HD patients. However, the levels elevated significantly (10.6%, <i>p</i> = 0.03) in online HDF patients. <b><i>Discussion/Conclusion:</i></b> These results indicated that the time-dependent deterioration of the nutritional state in very elderly dialysis patients was inevitable; however, such deterioration was not prominent in online HDF patients. Moreover, the lipid profile showed unique changes in online HDF patients. In order to treat very elderly dialysis patients, online HDF should preferentially be taken into consideration because the maintenance of general condition seems to be a practical goal against the natural time-dependent deterioration.

Life history contrasts in nutritional state and return probability of post-spawned Atlantic salmon

Using non-lethal tissue biopsies, we investigated somatic energy, lipid composition, and condition in post-spawned Atlantic salmon (kelts, n = 69) returning to sea in the spring and explored contrasts as a function of previous migration- and spawning history, length and sex. Using mark-recapture analysis, we also explored linkages between spawning history and probability of future repeat spawning. Lipid density was significantly higher in previously spawned individuals compared to first time spawned fish, and in females compared to males. Fatty acid composition differed significantly among spawning histories. Return rates to consecutive spawning the following year were consistent with spawning history dependent differences in lipid density, as first time spawned kelts had lower return rates compared to consecutive repeat spawned kelts. We suggest that spawning history related contrasts in nutritional state in post-spawned Atlantic salmon may be a carry-over effect of differences in the feeding habitat as affected by spawning-history dependent migration strategies. Alternatively, it may represent an adaptive response to increased survival and recovery potential with age.