Night Fasting Research Articles

Psychosocial childbearing stress and metabolic control in pregnant diabetics.

The authors tested the relationship between psychosocial childbearing stress factors and metabolic control in a research sample of 39 pregnant insulin-dependent diabetic women. Subjects were selected using rigorous exclusion criteria from a population of more than 200 pregnant diabetic patients assessed in a University National Institutes of Health Center. Metabolic control was determined by plasma levels of preprandial day, night, and early morning fasting glucose, urinary ketones, and glycosylation of hemoglobin. Differences in plasma glucose concentrations and urinary ketone levels at several times during the day and night were associated with psychosocial stress factors. A similar relationship between stress and levels of diabetic control could not be demonstrated by hemoglobin A1 assay, a result contradicting most prior studies of adolescent populations. These findings are compatible with a biopsychosocial model of diabetes mellitus and emphasize the importance of using several different measures of diabetic control to determine stress-control relationships.

The effect of cholestyramine on liver HMG-CoA reductase and cholesterol 7α-hydroxylase in various laboratory animals

The activity of HMG-CoA reductase and cholesterol 7α-hydroxylase was assayed in the liver of rats, rabbits, hamsters and guinea pigs at the minimum of the day cycle and after one night fasting. The amount of HMG-CoA reductase, as determined after its complete dephosphorylation in vitro was of the same order of magnitude in the tested species. The dephosphorylated active form of the enzyme was detectable only in the rat. Cholesterol 7α-hydroxylase activity was also much higher in the rat. Cholestyramine treatment stimulated the activity of both enzymes. In particular, the ratio between active and inactive HMG-CoA reductase in rabbits, hamsters and guinea pigs became of the same order of magnitude of that found in rats.

Theophylline and Diet

Regarding the article by Feldman et al1 concerning the interaction between diet and theophylline metabolism, we found ourselves wondering about the validity of one of their basic assumptions. The authors assumed that the bioavailability of the drug is "absolute," regardless of the various diets. This assumption is based on a study2 that compared two different sources of theophylline and found their bioavailability to be almost 100%. But in this study2 the drugs were taken by adults, as a single test dose, after a night's fast, with two hours of fasting after taking the drug.

Factors affecting the supply of glucose to the heart of the rat, in vivo.

1. The influx of glucose into the heart of intact, living, anaesthetized rats was measured when the levels of insulin the blood were (a) low (as a result of fasting), (b) normal, and (c) high (as a result of injecting insulin). The findings showed that the transport of glucose into cardiac cells is carrier-mediated and is strongly insulin-independent. 2. The major barrier to the supply glucose to the heart from the circulating blood is at the surface membrane of the cardiac cells, rather than at the endothelium of the cardiac capillaries. 3. The extracellular space of the heart was measured and was found to be approximately 25% of the cardiac tissue. 4. During life, glucose, as well as its analogue, 3-O-methylglucose passes across the membranes of the cells of the heart by means of a transport system which is strongly dependent upon insulin and appears to be carried-mediated. A likely explanation for the effect of insulin is that it increases considerably the affinity of the transport carrier for glucose. Saturation of the carrier takes place when the levels of insulin and of glucose in the blood are high. However, when the concentration of insulin is low, e.g. during a fast, the affinity of the carrier for glucose is reduced so that saturation cannot be demonstrated. 5. It is suggested that the low level of insulin that is found in the blood in the early morning, which is due to the night fast, may lead to the cardiac dysfunction which often develops at that time.

Acid-base status in nonketotic diabetics.

Measurements of acid-base parameters in arterial blood were performed in patients with different types of well-controlled diabetes. The diabetics showed normal acid-base status in recumbent position after a night's fast. In contrast to the control subjects, the diabetics showed, on change of posture, an enhanced ventilation, leading to a lowering of Pco2 by 2-3 mm Hg and a rise in pH of 0.02 about 30 min after erect position was assumed. The higher blood pH in diabetics seemed to persist during daytime.

Study of Lipid Profile in Shift Workers

Background: The present study was undertaken to evaluate the changes of serum lipid profile in apparently healthy shift workers and non shift workers to identify the possible high risk factors for developing atherosclerotic changes. Methods: Serum Total Cholesterol, Triglyceride, HDL-Cholesterol and LDL-Cholesterol levels were estimated and blood pressure was measured in apparently healthy adult shift worker and non shift worker participants. Total 60 subjects age ranged from 20-50 years were selected, of whom 30 were shift workers (Study) for at least one year and 30 were non shift workers (control). Height, weight and resting blood pressure of all the subjects were recorded before collection of blood. Blood samples were collected after over night fasting for estimation of serum lipid and lipoprotein levels and were measured by standard laboratory technique. Data were analyzed by unpaired ‘t' test. Results: The mean serum Total Cholesterol and LDL-Cholesterol levels were significantly higher in shift workers compared to those of non shift workers. Again mean serum Triglyceride and HDL-Cholesterol levels in the shift workers did not differ significantly from that of non shift workers. These changes may be related to internal desynchronization due to disruption of circadian rhythm. Conclusion: The changes in serum lipid and lipoprotein levels with the exception of HDL-Cholesterol and Triglyceride in the subjects engaged in shift work may put them at increased risk for coronary artery disease. Keywords: Circadian Rhythm; Lipid Profile; Shift-work DOI:10.3329/jbsp.v2i0.982 J Bangladesh Soc Physiol. 2007 Dec;(2): 34-37.

Effect of glucose and fat loading on lipoprotein lipase activity in plasma and tissues of diabetes.

The authors previously noted a more significantly decreased response of lipoprotein lipase activity to dextran sulfate injection in diabetic patients than in normal subjects and suggested that the lowered plasma lipoprotein lipase activity may contribute to hypertriglyceridemia in diabetic patients. In the present report the authors have studied on human subjects and rats with and without diabetes, the regulation of lipoprotein hpase activity in postdextransulfate plasma and tissues following administration of glucose or fat. In normal subjects the response of plasma lipoprotein lipase activity to injected dextran sulfate one hr. after feeding or oral glucose administration was significantly higher than the response after an over night fast. In diabetic patients, however, the difference between feeding or glucose administration and over night fast was insignificant. In normal rats the increase of tissue lipoprotein lipase activity to intravenously administered glucose was significant in adipose tissue and insignificant in muscles. After intravenous fat administration no significant changes were observed either in aciinose tissue or in muscles. In alloxan diabetic rats decrease in activity of lipoprotein lipase was significant in adipose tissue, but insignificant in heart muscle and diaphragm compared with normal rats. From the facts above it is suggested that markedly elevated plasma lipoprotein lipase activity after glucose loading in normal subjects is released from tissue in response to intravenously administered dextran sulfate. The authors have also discussed the probability of induction of lipoprotein lipase in adipose tissue by the metabolic effects of glucose and/or insulin.

Effect of fasting on fibrinolysis and blood coagulation

The effect of 60 hours' fasting on fibrinolytic activity, Stypven time and serum cholesterol was studied in 12 healthy men. The fibrinolysis time was 32.0 hours after a night's fasting, 19.7 hours after 36 hours' fasting and 14.4 hours after 60 hours' fasting. The change was statistically significant after 36 hours of fasting, and the fibrinolytic activity did not change significantly during the following fasting day. The Stypven coagulation time after a night's fasting was 19.3 seconds; after 36 hours' fasting, 20.6 seconds; and after 60 hours' fasting, 22.5 seconds. The change was statistically almost significant after 60 hours' fasting. After fasting for 36 hours the change was not statistically significant. The serum cholesterol increased significantly during 12 to 36 hours' fasting (from 259 to 281 mg.%) and increased significantly during the next 24 hours of fasting (to 296 mg.%).

Gastric Mucin Secretion in Gastro-duodenal Ulcerative Disease

It was shown1 that commercial gastric mucin when subjected to peptic digestion and subsequent precipitation with alcohol at 70% concentration, yielded upon hydrolysis characteristic values for total nitrogen and total reducing substances. This suggested the use of a reduction method for the quantitation of mucin. Obviously before such a method can be applied to gastric juice, it is necessary to remove all other reducing substances, or to use a procedure for obtaining gastric juice not subject to their presence. The former procedure would be capable of wider application and work is in progress with this end in view. Our present interest is in the variations in mucin content of gastric secretion, when juice is obtained from the fasting stomach by means of an alcohol test meal under conditions excluding other reducing substances.In following the curve of mucin secretion, the stomach is emptied after a night's fast, basal secretory rate established, then 250 cc. of 7% ethyl alcohol is given and samples remove...

Lactic acid of normal and pathological spinal fluids.

In 1917 Levinson1 observed that spinal fluids from cases of epidemic meningitis immediately after withdrawal had a subnormal pH. This was in some instances further decreased when the fluids were permitted to stand at room temperature unstoppered. However, normal and tuberculous meningitic fluids when freshly drawn showed similar figures for pH, and the pH increased on standing, particularly in the tuberculous fluids. Levinson believed that the lowering of the pH of the spinal fluid in meningococcus meningitis was due to the accumulation of lactic acid in the fluid, but he presented no data to substantiate this explanation.In the present communication, data are presented for the sugar and lactic acid of the spinal fluid of normals, miscellaneous pathological conditions and meningitis. Clausen's method was employed for the determination of the lactic acid, and the Folin-Wu procedure for the sugar.Specimens of spinal fluid obtained from five normal adults, after a night's fast and rest, showed lactic acid co...