Long-term effects of calorie or protein restriction on serum IGF-1 and IGFBP-3 concentration in humans.
Thromb Res. 2009 Mar;123(5):740-4. Epub 2008 Sep 10. PMID: 18843793
Luigi Fontana, Edward P Weiss, Dennis T Villareal, Samuel Klein, John O Holloszy
Reduced function mutations in the insulin/IGF-I signaling pathway increase maximal lifespan and health span in many species. Calorie restriction (CR) decreases serum IGF-1 concentration by ~40%, protects against cancer and slows aging in rodents. However, the long-term effects of CR with adequate nutrition on circulating IGF-1 levels in humans are unknown. Here we report data from two long-term CR studies (1 and 6 years) showing that severe CR without malnutrition did not change IGF-1 and IGF-1 : IGFBP-3 ratio levels in humans. In contrast, total and free IGF-1 concentrations were significantly lower in moderately protein-restricted individuals. Reducing protein intake from an average of 1.67 g kg(-1) of body weight per day to 0.95 g kg(-1) of body weight per day for 3 weeks in six volunteers practicing CR resulted in a reduction in serum IGF-1 from 194 ng mL(-1) to 152 ng mL(-1). These findings demonstrate that, unlike in rodents, long-term severe CR does not reduce serum IGF-1 concentration and IGF-1 : IGFBP-3 ratio in humans. In addition, our data provide evidence that protein intake is a key determinant of circulating IGF-1 levels in humans, and suggest that reduced protein intake may become an important component of anticancer and anti-aging dietary interventions.
Article Published Date : Mar 01, 2009
Treatment of chronic uremic patients with protein-poor diet and oral supply of essential amino acids. I. Nitrogen balance studies.
Clin Nephrol. 1975;3(5):187-94. PMID: 1149343
J Bergström, P Fürst, L O Norée
Twenty-six nitrogen balance studies were performed in 15 patients with severe uremia (Ccr mean value 5.1, range 2.3-8.5 ml/min) treated with an unselected protein-poor (16-20 g protein/day corresponding to 2.6-3.2 g N/day) diet and oral supply of the essential amino acids including histidine (2.6 g N/day). The general condition improved and the concentration of serum urea nitrogen decreased. The nitrogen balance, corrected for changes in total urea pool, was negative on the diet alone,-1.46 plus or minus 1.15 g N/day (mean plus or minus SD), but was positive when the essential amino acids were supplied, plus 0.84 plus or minus 0.68 g N/day. In four patients studied after 3 to 26 months of diet and amino acid therapy, during which time a further deterioriation of the renal function had occurred, the nitrogen balance was around zero in three and negative in one patient (-1.2 g N/day). The results show that it is possible with our new regimen to attain positive nitrogen balance or nitrogen equilibrium in severely uremic patients without excessive accumulation of urea in the body fluids.
Article Published Date : Jan 01, 1975
Treatment of chronic uremic patients with protein-poor diet and oral supply of essential amino acids. II. Clinical results of long-term treatment.
Clin Nephrol. 1975;3(5):195-203. PMID: 1149344
L O Norée, J Bergström
Twenty-six uremic patients - serum urea nitrogen (SUN) 110 MG/100 ml plus or minus 22.8 (mean plus or minus SD), serum cretinine (S-Creat) 13.2 mg/100 ml plus or minus 2.27, ratio SUN/S-Creat 8.6 plus or minus 2.26, and endogenous creatinine clearance (Ccr) 3.86 plus or minus 1.41 ml/min - were treated for three months or longer with an unselected protein-poor (16-20 g protein/day) diet with oral supply of the essential amino acids including histidine in high doses as coated tablets. The amino acids were instituted after an initial diet only period (mean 0.4 months). The average treatment time was 8.4 months (range 2.7-33.6). An improvement of the general condition was obtained, persisting for several months. SUN and SUN/S-Creat decreased on the diet alone, continued to decrease after one month, and increased slightly again after three months of treatment, but did not reach the initial levels for several months in spite of an almost doubled nitrogen intake. S-Creat increased after six months indicating a further deterioration of the renal function. In patients with initially low serum total protein (smaller than 6.5 g/100 ml, 9 patients), albumin (smaller than 3.5 g/100 ml, 10 patients), and total iron-binding capacity (smaller than 260 mug/100 ml, 11 patients) the values increased after one month on amino acids and were thereafter stable. No signs of bleeding tendency, progressive muscle atrophy, or progressive peripheral neuropathy were observed. - Five patients died due to cardiovascular maladies. A further 13 patients were withdrawn for medical reasons (overhydration, 4 patients; hypertension, 1 patient; nausea and vomiting, 7 patients; and pericarditis, 1 patient). - The renal function improved in one patient. Four patients received home dialysis training, three a kidney transplant. - The results indicate that it is possible to keep severely uremic patients free from uremic symptoms, counteract protein depletion, and even improve the nutritional status during long-term treatment with an unselected protein-poor diet supplementd with essential amino acids.
Article Published Date : Jan 01, 1975
Alkaline Diet and Metabolic Acidosis: Practical Approaches to the Nutritional Management of Chronic Kidney Disease.
J Ren Nutr. 2017 Dec 05;:
Authors: Rodrigues Neto Angéloco L, Arces de Souza GC, Almeida Romão E, Garcia Chiarello P
The kidneys play an extremely important role in maintaining the body acid-base balance by excreting nonvolatile acids and regenerating and reabsorbing bicarbonate in the kidney tubules. As the individual loses their kidney function, renal excretion of nonvolatile acid produced by metabolism of the diet is impaired, resulting in low-grade metabolic acidosis. With this in mind, it is relevant to better understand the dietary aspects related to the acid-base balance in chronic kidney disease metabolic acidosis and try to provide possible strategies for the nutritional management of these cases. The type of diet can deeply affect the body by providing acid or base precursors. Generally speaking, foods such as meat, eggs, cheese, and grains increase the production of acid in the organism, whereas fruit and vegetables are alkalizing. On the other hand, milk is considered neutral as well as fats and sugars, which have a small effect on acid-base balance. The modern Western-type diet is deficient in fruits and vegetables and contains excessive animal products. Thus metabolic acidosis may be exacerbated by a contemporary Western diet, which delivers a high nonvolatile acid load. The remaining acid is neutralized or stored within the body. Bone and muscle are lost to neutralize the acid and serum bicarbonate falls. Early studies suggest that lowering the dietary acid load with a reduced protein content and vegetable proteins replacements, associated with an increase in fruits and vegetables intake can improve the metabolic parameters of acidosis, preserve bone and muscle, and slow the glomerular filtration rate decline. More studies focusing on the effects of controlled dietary interventions among chronic kidney disease patients are needed to determining the optimal target for nutritional therapy.
PMID: 29221627 [PubMed - as supplied by publisher]