Adjunctive therapies in nutritional support

Proliferator-activated receptor gamma Pro12Ala interacts with the insulin receptor substrate 1 Gly972Arg and increase the risk of insulin resistance and diabetes in the mixed ancestry population from South Africa

BACKGROUND

The peroxisome proliferator-activated receptor gamma (PPARG), Pro12Ala and the insulin receptor substrate (IRS1), Gly972Arg confer opposite effects on insulin resistance and type 2 diabetes mellitus (T2DM). We investigated the independent and joint effects of PPARG Pro12Ala and IRS1 Gly972Arg on markers of insulin resistance and T2DM in an African population with elevated risk of T2DM. In all 787 (176 men) mixed-ancestry adults from the Bellville-South community in Cape Town were genotyped for PPARG Pro12Ala and IRS1 Gly972Arg by two independent laboratories. Glucose tolerance status and insulin resistance/sensitivity were assessed.

RESULTS

Genotype frequencies were 10.4% (PPARG Pro12Ala) and 7.7% (IRS1 Gly972Arg). Alone, none of the polymorphisms predicted prevalent T2DM, but in regression models containing both alleles and their interaction term, PPARG Pro12 conferred a 64% higher risk of T2DM. Furthermore PPARG Pro12 was positively associated in adjusted linear regressions with increased 2-hour post-load insulin in non-diabetic but not in diabetic participants.

CONCLUSION

The PPARG Pro12 is associated with insulin resistance and this polymorphism interacts with IRS1 Gly972Arg, to increase the risk of T2DM in the mixed-ancestry population of South Africa. Our findings require replication in a larger study before any generalisation and possible application for risk stratification.

Beneficial effect of chungkukjang on regulating blood glucose and pancreatic beta-cell functions in C75BL/KsJ-db/db mice

The current study investigated the antidiabetic effect of chungkukjang, a widely used traditional Korean soybean fermentation food, in a type 2 diabetic animal model, C57BL/KsJ-db/db mice. After a 2-week acclimation period, the db/db mice (male, 5 weeks old) were divided into three groups: diabetic control (AIN-76 diet), chungkukjang (5 g/100 g of diet), and rosiglitazone (0.005 g/100 g of diet). The supplementation of chungkukjang induced a significant reduction of blood glucose and glycosylated hemoglobin level, and it improved insulin tolerance compared to the diabetic control group. Plasma and pancreatic insulin levels of the chungkukjang-supplemented group were significantly higher than those of the diabetic control mice, and the plasma glucagon level was also significantly different. The supplementation of chungkukjang and rosiglitazone significantly elevated hepatic glucokinase activity with a simultaneous reduction of glucose-6-phosphatase and phosphoenolpyruvate carboxykinase activity in the db/db mice compared to the diabetic control mice. In addition, the chungkukjang-supplemented group had an increased hepatic glycogen content compared to the diabetic control and rosiglitazone-supplemented groups. Consequently, these results suggest that chungkukjang may be beneficial in improving insulin resistance and hyperglycemia in type 2 diabetic animals that are partly medicated by the regulation of hepatic glucose enzymes and insulin sensitivity in peripheral tissues.

Effects of glutamine-enriched total parenteral nutrition on acute pancreatitis

AIM

This study was performed to determine the effects of glutamine enriched total parenteral nutrition (TPN) on the patients with acute pancreatitis (AP).

METHOD

Forty patients with AP, who had Ranson's score between 2 and 4 received either standard TPN (control group) or TPN with glutamine (treatment group). The patients in the treatment group received TPN containing 0.3 g/kg/days glutamine. At the end of the study, patients were evaluated for nutritional and inflammatory parameters, length of TPN and length of hospital stay.

RESULTS

The length of TPN applications were 10.5+/-3.6 days and 11.6+/-2.5 days, and the length of hospital stays were 14.2+/-4.4 and 16.4+/-3.9 days for the treatment and control groups (NS), and the complication rates in the treatment and control groups were 10 and 40%, respectively (P<0.05). The transferrin level increased by 11.7% in the group that received glutamine-enriched TPN (P<0.05), whereas the transferrin level decreased by 12.1% in the control group (NS). At the end of the study, slight but not significant changes were determined in both groups in fasting blood sugar, albumin, blood urea nitrogen (BUN), creatinine, total cholesterol concentrations, aspartate aminotransferase (AST), alanine transaminase (ALT) and lactate dehydrogenase (LDH) activities, leukocytes, CD(4), CD(8), serum Zn, Ca and P levels compare to the baseline levels (NS). Significant decreases were determined in serum lipase, amylase activities and C-reactive protein (CRP) levels in both groups (P<0.05).

CONCLUSIONS

The results of this study have shown that glutamine supplementation to TPN have beneficial effects on the prevention of complications in patients with AP.

Methylprednisolone sodium succinate in pediatric parenteral nutrition: influence of vehicle injection

Many drugs can be administered in parenteral nutrient mixtures, but no work on the delivery of corticoids by such means is reported. We studied the influence of pediatric parenteral nutrient mixtures on the kinetic parameters of the corticoid methylprednisolone injected in an intravenous bolus in rabbits as its sodium succinate ester. Four groups of six male New Zealand rabbits were used. After extraction, the plasma drug concentrations were measured by high performance liquid chromatography. The distribution volume of the ester and the clearance rates of the two entities (ester and methylprednisolone) were lowered in the presence of a lipid emulsion. The description of these pharmacokinetic parameters provides a basis for a preclinical study of 24h administration of methylprednisolone in a parenteral nutrient mixture.

Growth hormone decreases muscle glutamine production and stimulates protein synthesis in hypercatabolic patients

We determined the effects of 24-h recombinant human growth hormone (rhGH) infusion into a femoral artery on leg muscle protein kinetics, amino acid transport, and glutamine metabolism in eight adult hypercatabolic trauma patients. Metabolic pathways were assessed by leg arteriovenous catheterization and muscle biopsies with the use of stable amino acid isotopes. Muscle mRNA levels of selected enzymes were determined by competitive PCR. rhGH infusion significantly accelerated the inward transport rates of phenylalanine and leucine and protein synthesis, whereas the muscle protein degradation rate and cathepsin B and UbB polyubiquitin mRNA levels were not significantly modified by rhGH. rhGH infusion decreased the rate of glutamine de novo synthesis and glutamine precursor availability, total branched-chain amino acid catabolism, and nonprotein glutamate utilization. Thus net glutamine release from muscle into circulation significantly decreased after rhGH administration ( approximately 50%), whereas glutamine synthetase mRNA levels increased after rhGH infusion, possibly to compensate for reduced glutamine precursor availability. We conclude that, after trauma, the anticatabolic action of rhGH is associated with a potentially harmful decrease in muscle glutamine production.

Anorexia in response to acute illness

Anorexia associated with acute illness remains one of the most common, challenging, and difficult symptoms to treat. Surprisingly, little attention has been devoted to development of interventions to reverse this form of anorexia. Although incomplete, current understanding of the mechanisms responsible for illness-induced anorexia is sufficient to suggest therapeutic approaches. In this article, the major physiologic mechanisms underlying illness-induced anorexia are described. In addition, potential moderating effects of social, psychologic, and environmental factors are discussed. This information was used to develop recommendations for the treatment of anorexia. A majority of these interventions, however, are not research based. Further advances in the treatment of illness-induced anorexia will require greater understanding of the complex, interactive effects of psychologic, environmental, and biologic factors on eating behavior during illness. Therefore, areas requiring continued investigation are also outlined.