The nutritional status of 59 randomly-selected general surgical ward patients (38 men, 21 women; mean age, 50.4 years) was studied (using both clinical assessment and objective analysis methods) to measure the reproducibility and validity of clinical assessment. Objective nutritional assessment included anthropometric and other (e.g., serum albumin, lymphocyte count, total-body nitrogen) measurements. Clinical status was assessed (history taking and physical exam) by 2 physicians before surgery. Clinical assessment reproducibility between the 2 physicians was demonstrated by independent agreement on clinical classification of 48 of the patients (81%). Validity was demonstrated by correlation of clinical classification with objective measurement of nutritional status; and with 3 measures of hospital morbidity (infection incidence, antibiotic use, and length of hospital stay). It is concluded that clinical assessment is reproducible and valid since it correlated well with objective measurements and morbidity. (wz)

Nutritional assessment: A comparison of clinical judgement and objective measurements

To determine the independent contribution of specific immunologic and nutritional factors on survival in HIV-1 disease, CD4 cell count, antiretroviral treatment, plasma levels of vitamins A, E, B6, and B12 and minerals selenium and zinc were considered in relation to relative risk for HIV-related mortality. Immune parameters and nutrients known to affect immune function were evaluated at 6-month intervals in 125 HIV-1-seropositive drug-using men and women in Miami, FL, over 3.5 years. A total of 21 of the HIV-1-infected participants died of HIV-related causes during the 3.5-year longitudinal study. Subclinical malnutrition (i.e., overly low levels of prealbumin, relative risk [RR] = 4.01, p < 0.007), deficiency of vitamin A (RR = 3.23, p < 0.03), vitamin B12 deficiency (RR = 8.33, p < 0.009), zinc deficiency (RR = 2.29.1, p < 0.04), and selenium deficiency (RR = 19.9, p < 0.0001) over time, but not zidovudine treatment, were shown to each be associated with HIV-1-related mortality independent of CD4 cell counts <200/mm3 at baseline, and CD4 counts over time. When all factors that could affect survival, including CD4 counts <200/mm3 at baseline, CD4 levels over time, and nutrient deficiencies were considered jointly, only CD4 counts over time (RR = 0.69, p < 0.04) and selenium deficiency (RR = 10.8, p < 0.002) were significantly associated with mortality. These results indicate that selenium deficiency is an independent predictor of survival for those with HIV-1 infection.

High risk of HIV-related mortality is associated with selenium deficiency

Body composition studies in patients with the acquired immunodeficiency syndrome.

The name "transthyretin" reflects the dual physiological roles of this tetrameric unglycosylated plasma protein. TTR is one of three specific carrier proteins involved in the transport of both thyroid hormones and of retinol through the mediation of RBP. TTR is a product of the visceral compartment, and its hepatic synthesis is exquisititely sensitive to both the adequacy and levels of protein and energy intakes--hence the proposal of TTR as a nutritional marker. To date, 38 TTR variants have been described, most of which are associated with variable degrees of cardiac and/or neural tissue amyloid deposits. All known variants arise from a single AA substitution due to single point mutation in the coding region of the TTR gene. Under acute stress conditions, the synthesis of TTR, RBP, and CBG is abruptly depressed by a cytokine-directed orchestration of new metabolic priorities, with a redistribution of organ and tissue protein pools. It is proposed that TTR, RBP, and CBG behave as acute-booster reactants (ABRs), actively participating in the cascade of metabolic events characterizing the stress reaction along pathways best explained by the free hormone/vitamin hypothesis. The latter is governed by the law of mass action--the spontaneous dissociation and instant uptake by hepatocytes of the ligands freed from their specific carrier proteins, which creates a transient hyperthyroid, hyperretinoid, and hypercortisolic climate. This response generally does not exceed four or five days because the initial impact of injury normally subsides, but it may last longer if complications occur. The magnitude and adequacy of the stress responses depend on the preceding nutritional status as assessed by TTR plasma levels and are proportionate to the severity of insult. Clinical, animal, and molecular studies concur to demonstrate the dualistic stimulatory or inhibitory effects triggered by the ligands, whose unmetabolized fractions are excreted in the urinary output. Thyroid hormones and retinoids appear to control the early maturation processes and the synthesis of primary transcripts, whereas cortisol preferentially modulates the secondary responses and confers a protective effect on healthy tissues. During acute stress, the evolutionary patterns of visceral proteins and inflammatory markers exhibit compulsory mirror images. However, they change in independent ways under more chronic circumstances. A relatively simple biochemical micromethod based on the simultaneous measurement of plasma TTR, albumin, CRP, and orosomucoid aggregated into a PINI is proposed for the early recognition and follow-up of both nutritional and inflammatory facets of the disease spectrum.

W.P.T. James

Papers

Rapid-turnover transport proteins: an index of subclinical protein-energy malnutrition