Influence Serum Cholesterol Levels Research Articles

GUAR GUM IN THERAPEUTICS: A SUCCINCT EXPLORATION

Guar gum, extracted from the seeds of Cyamopsis tetragonolobus, has gained prominence for its unique properties, forming a thick gel in water and releasing fatty acids through fermentation. Originating in Pakistan and India, it found industrial significance in the US during the 1940s. The galactomannan in guar's endosperm, a polysaccharide of d-mannose and d-galactose, imparts rapid solubility, pH stability, and biodegradability. Beyond its industrial applications, guar gum exhibits a myriad of health benefits. Delving into the botanical symphony of guar seeds reveals a poetic composition, and enzymatic exploration unravels the whimsical ballet of galactose side groups. Guar gum transcends its botanical origins to become a dietary sage, influencing serum cholesterol levels and aiding in weight management. Its journey through the digestive system orchestrates nuanced reductions in blood glucose and insulin, showcasing its potential for diabetes assistance.The manufacturing process involves splitting, hydration, and various treatments, resulting in guar gum's characteristics as a thickening agent with tasteless and odorless properties. Stability studies affirm its consistent performance over time, and its safety for target species, consumers, and the environment is established. Exploring guar gum's therapeutic applications reveals its potential in wound healing, inflammatory bowel disease treatment, and as a preventive measure against ulcers. Its role as a dietary fiber extends to managing irritable bowel syndrome symptoms, reducing blood sugar and cholesterol levels, promoting weight loss, and aiding in regular bowel movements. The article recommends a daily intake of 28g for adult women and 36g for men, achievable through the consumption of guar gum. Clinical studies demonstrate its positive impact on duodenal ulcers, providing relief, increasing satiety, and preventing symptoms. With its multifaceted applications, guar gum emerges as a fascinating substance intertwining chemistry, medicine, and industry.

Differences in Cholesterol Metabolism, Hepato-Intestinal Aging, and Hepatic Endocrine Milieu in Rats as Affected by the Sex and Age.

Age and sex influence serum cholesterol levels, but the underlying mechanisms remain unclear. To investigate further, we measured cholesterol, precursors (surrogate synthesis markers), degradation products (oxysterols and bile acid precursors) in serum, the liver, jejunum, and ileum, as well as serum plant sterols (intestinal absorption markers) in male and female Wistar rats (4 and 24 months old). The analysis of histomorphometric and oxidative stress parameters (superoxide dismutase, catalase, glutathione-related enzyme activities, lipid peroxide, and protein carbonyl concentrations) in the liver and jejunum offered further insights into the age- and sex-related differences. The hepatic gene expression analysis included AR, ERα, and sex-specific growth hormone-regulated (Cyp2c11 and Cyp2c12) and thyroid-responsive (Dio1, Tbg, and Spot 14) genes by qPCR. We observed age-related changes in both sexes, with greater prominence in females. Aged females had significantly higher serum cholesterol (p < 0.05), jejunum cholesterol (p < 0.05), and serum plant sterols (p < 0.05). They exhibited poorer hepato-intestinal health compared with males, which was characterized by mild liver dysfunction (hydropic degeneration, increased serum ALT, p < 0.05, and decreased activity of some antioxidant defense enzymes, p < 0.05), mononuclear inflammation in the jejunal lamina propria, and age-related decreases in jejunal catalase and glutathione peroxidase activity (p < 0.05). Aged females showed increased levels of 27-hydroxycholesterol (p < 0.05) and upregulated ERα gene expression (p < 0.05) in the liver. Our study suggests that the more significant age-related increase in serum cholesterol in females is associated with poorer hepato-intestinal health and increased jejunal cholesterol absorption. The local increase in 27-hydroxycholesterol during aging might reduce the hepatoprotective effects of endogenous estrogen in the female liver.

Does Dietary Cholesterol Matter?

An ongoing dispute in the nutrition field is whether dietary cholesterol contributes significantly to elevated serum cholesterol and to atherosclerotic disease. Carefully controlled metabolic studies have shown that high-cholesterol intakes cause moderate increases in serum cholesterol levels. It is been difficult to verify this in population studies because of confounding factors. Nonetheless, meta-analysis of controlled studies documents a cholesterol-raising action of dietary cholesterol. Most of this effect occurs in low-density lipoproteins (LDLs), but the cholesterol content of other lipoproteins can be increased as well. Moreover, population studies strongly suggest that dietary cholesterol is atherogenic beyond any rise in LDL concentrations. It must be emphasized that dietary cholesterol is only one of several dietary factors influencing serum cholesterol levels. Others include saturated fatty acids, trans fatty acids, soluble fiber, and total caloric intake. To achieve substantial serum cholesterol lowering, favorable changes in all of these factors must be combined. To maximize cardiovascular risk reduction, a lifetime of a healthy diet is needed. Reduced cholesterol intake is only one of several factors required to achieve such a diet. In addition, reduction of cholesterol absorption can enhance serum cholesterol lowering. This can be attained by the addition of plant sterols or plant stanols to the diet or by use of ezetimibe, a cholesterol absorption blocker. By combining dietary cholesterol reduction with other cholesterol-lowering modalities, it should be possible to substantially reduce atherosclerosis throughout life short of using cholesterol-lowering drugs that act systemically.

Serum Proprotein Convertase Subtilisin/Kexin Type 9 and Cell Surface Low-Density Lipoprotein Receptor

Background— Proprotein convertase subtilisin/kexin type 9 (PCSK9) modulates low-density lipoprotein (LDL) receptor (LDLR) degradation, thus influencing serum cholesterol levels. However, dysfunctional LDLR causes hypercholesterolemia without affecting PCSK9 clearance from the circulation. Methods and Results— To study the reciprocal effects of PCSK9 and LDLR and the resultant effects on serum cholesterol, we produced transgenic mice expressing human (h) PCSK9. Although hPCSK9 was expressed mainly in the kidney, LDLR degradation was more evident in the liver. Adrenal LDLR levels were not affected, likely because of the impaired PCSK9 retention in this tissue. In addition, hPCSK9 expression increased hepatic secretion of apolipoprotein B–containing lipoproteins in an LDLR-independent fashion. Expression of hPCSK9 raised serum murine PCSK9 levels by 4.3-fold in wild-type mice and not at all in LDLR −/− mice, in which murine PCSK9 levels were already 10-fold higher than in wild-type mice. In addition, LDLR +/− mice had a 2.7-fold elevation in murine PCSK9 levels and no elevation in cholesterol levels. Conversely, acute expression of human LDLR in transgenic mice caused a 70% decrease in serum murine PCSK9 levels. Turnover studies using physiological levels of hPCSK9 showed rapid clearance in wild-type mice (half-life, 5.2 minutes), faster clearance in human LDLR transgenics (2.9 minutes), and much slower clearance in LDLR −/− recipients (50.5 minutes). Supportive results were obtained with an in vitro system. Finally, up to 30% of serum hPCSK9 was associated with LDL regardless of LDLR expression. Conclusions— Our results support a scenario in which LDLR represents the main route of elimination of PCSK9 and a reciprocal regulation between these 2 proteins controls serum PCSK9 levels, hepatic LDLR expression, and serum LDL levels.

Abstract 123: Reciprocal Regulation of Plasma PCSK9 and Cell-surface Low-density Lipoprotein Receptor

Proprotein convertase subtilisin/kexin type 9 (PCSK9) modulates low-density lipoprotein (LDL) receptor (LDLR) degradation, thus influencing serum cholesterol levels. On the other hand, LDLR binds to and clears PCSK9 from the circulation, thus modulating its serum levels. To study the global and reciprocal effects of PCSK9 and LDLR on serum cholesterol, we developed transgenic mice expressing human (h) PCSK9 and characterized its activity, serum levels, and tissue distribution. Serum hPCSK9 concentration in transgenic mice was 2181±423 ng/ml, about 10 times higher than normal level in human serum. Although hPCSK9 was expressed mainly in the kidney, LDLR degradation activity was most evident in the liver and small intestine. In contrast, LDLR levels were not affected by hPCSK9 expression in the adrenals and large intestine. On a chow diet, hPCSK9 transgenic mice on either C57BL/6 (wild-type, WT) or LDLR -/- background had higher cholesterol levels than their non-transgenic counterparts. Human PCSK9 transgenic mice had over a 4-fold increase in murine (m) PCSK9 serum levels compared to WT controls. However, transgenic expression of hPCSK9 in LDLR -/- mice did not affect the already elevated levels of mPCSK9. On the other hand, induction of hLDLR expression in transgenic mice caused a dramatic decrease in mPCSK9 levels. In addition hPCSK9 levels were increased by 2 fold in transgenic mice under LDLR -/- compare to WT background. Turnover studies with native PCSK9 showed rapid serum clearance in WT mice (half-life 5.2 min), whereas clearance was much slower in LDLR -/- recipient mice (50.5 min), and faster in hLDLR transgenic mice (2.9 min). In WT mice the injected PCSK9 accumulated in the liver and kidney but not in the adrenal gland. Ultracentrifugation and FLPC analysis showed that approximately one quarter of circulating hPCSK9 is associated with LDL, and that the LDL-associated PCSK9 is mainly in monomeric form. Our results show a reciprocal regulation between LDLR and PCSK9, which determines serum PCSK9 levels, hepatic LDLR expression, and serum LDL levels. Understanding these interactions will increase our knowledge of serum cholesterol homeostasis and should provide the basis for an intelligent design of anti-PCSK9 therapies.

Contribution of education level and dairy fat sources to serum cholesterol in Russian and Finnish Karelia: results from four cross-sectional risk factor surveys in 1992–2007

BackgroundFood habits vary by socio-economic group and geographic area. Data on socio-economic differences in food habits and in serum total cholesterol concentration from Russia are scarce. Our aim was to examine changes and educational differences in serum total cholesterol and in the consumption of major sources of saturated fat in two geographically neighbouring areas, Russian and Finnish Karelia, and to examine whether the foods associated with serum total cholesterol are different in the two areas.MethodsData from cross-sectional risk factor surveys from years 1992, 1997, 2002 and 2007 in the district of Pitkäranta, the Republic of Karelia, Russia (n = 2672), and North Karelia, Finland (n = 5437), were used. The analyses included two phases. 1) To examine the differences in cholesterol by education, the means and 95% confidence intervals for education groups were calculated for each study year. 2) Multivariate linear regression analysis was employed to examine the role of butter in cooking, butter on bread, fat-containing milk and cheese in explaining serum total cholesterol. In these analyses, the data for all four study years were combined.ResultsIn Pitkäranta, serum total cholesterol fluctuated during the study period (1992–2007), whereas in North Karelia cholesterol levels declined consistently. No apparent differences in cholesterol levels by education were observed in Pitkäranta. In North Karelia, cholesterol was lower among subjects in the highest education tertile compared to the lowest education tertile in 1992 and 2002. In Pitkäranta, consumption of fat-containing milk was most strongly associated with cholesterol (β=0.19, 95% CI 0.10, 0.28) adjusted for sex, age, education and study year. In North Karelia, using butter in cooking (β=0.09, 95% CI 0.04, 0.15) and using butter on bread (β=0.09, 95% CI 0.02, 0.15) had a significant positive association with cholesterol.ConclusionsIn the two geographically neighbouring areas, the key foods influencing serum cholesterol levels varied considerably. Assessment and regular monitoring of food habits are essential to plan nutrition education messages that are individually tailored for the target area and time.

Liposomal pravastatin inhibits tumor growth by targeting cancer-related inflammation

The chronic inflammatory environment of tumors is a target for novel antitumor therapeutic strategies. Besides cholesterol lowering effects, statins have been studied for their anti-inflammatory and immunomodulatory properties. These pleiotropic effects result mainly from the altered post-translational modification of GTP-binding proteins which regulate many intracellular pathways involved in cell growth and survival. Although pre-clinical studies suggest that statins may be effective anticancer agents required doses that are 100 to 500 fold higher than those needed to lower cholesterol levels. Furthermore, in view of their wide-ranging effects on cellular metabolism, target site-specific delivery is preferred. In this study, we investigated tumor-specific delivery of pravastatin using small long-circulating liposomes. In vitro studies on the effects of (liposomal) pravastatin on viability and proliferation of tumor cells, endothelial cells and macrophages revealed that the latter were the most sensitive cell type towards (liposomal) pravastatin treatment . In vivo, liposome-encapsulated pravastatin (5 mg/kg) inhibited murine B16F10-melanoma growth over 70% as compared to free pravastatin, which was ineffective. As expected, treatments did not influence serum cholesterol levels within the time frame of the study. At 48 h post-injection, 3 μg of pravastatin could still be recovered from the tumors of liposomal pravastatin treated mice, whereas pravastatin could not be detected in tumors of the free drug treated mice (i.e. < 20 ng). In contrast to the free drug, liposomal pravastatin treatment effectively inhibited the production of several pro-inflammatory/pro-angiogenic mediators involved in inflammation and angiogenesis, out of a range of a panel of 24 proteins studied. Furthermore, liposomal pravastatin treatment increased MHC class I protein expression in the tumor tissue whereas free drug showed no effect. Taken together, targeted delivery of statins can improve their tumor growth inhibiting activity by increasing local drug concentration and direct modulation of macrophage function. The antitumor activity seems to result primarily from a local inhibition of tumor inflammation and stimulation of antitumor immune response.

Modeling of environmental effects in genome-wide association studies identifies SLC2A2 and HP as novel loci influencing serum cholesterol levels.

Genome-wide association studies (GWAS) have identified 38 larger genetic regions affecting classical blood lipid levels without adjusting for important environmental influences. We modeled diet and physical activity in a GWAS in order to identify novel loci affecting total cholesterol, LDL cholesterol, HDL cholesterol, and triglyceride levels. The Swedish (SE) EUROSPAN cohort (N SE = 656) was screened for candidate genes and the non-Swedish (NS) EUROSPAN cohorts (N NS = 3,282) were used for replication. In total, 3 SNPs were associated in the Swedish sample and were replicated in the non-Swedish cohorts. While SNP rs1532624 was a replication of the previously published association between CETP and HDL cholesterol, the other two were novel findings. For the latter SNPs, the p-value for association was substantially improved by inclusion of environmental covariates: SNP rs5400 (p SE,unadjusted = 3.6×10−5, p SE,adjusted = 2.2×10−6, p NS,unadjusted = 0.047) in the SLC2A2 (Glucose transporter type 2) and rs2000999 (p SE,unadjusted = 1.1×10−3, p SE,adjusted = 3.8×10−4, p NS,unadjusted = 0.035) in the HP gene (Haptoglobin-related protein precursor). Both showed evidence of association with total cholesterol. These results demonstrate that inclusion of important environmental factors in the analysis model can reveal new genetic susceptibility loci.

Identification of Novel Hypocholesterolemic Peptides Derived from Bovine Milk β-Lactoglobulin

This study was designed to clarify the mechanisms of hypocholesterolemic action of β-lactoglobuline tryptic hydrolysate (LTH) and to identify the novel hypocholesterolemic peptide derived from LTH by screening using Caco-2 cells and animal studies. Serum and liver cholesterol levels were significantly lower in rats fed LTH than in those fed casein tryptic hydrolysate (CTH). The present study suggests that the inhibition of micellar solubility of cholesterol which causes the suppression of cholesterol absorption by a direct interaction between cholesterol mixed micelles, and LTH in the jejunal epithelia is part of the mechanism underlying the hypocholesterolemic action of LTH. Though no one could trace the hypocholesterolemic peptide to any protein origin, we identified, for the first time, a novel hypocholesterolemic peptide, Ile-Ile-Ala-Glu-Lys (IIAEK). Surprisingly, the present study provides the first direct evidence that a new hypocholesterolemic peptide derived from β-lactoglobuline can powerfully influence serum cholesterol levels and exhibit a greater hypocholesterolemic activity in comparison with that of medicine, β-sitosterol, in animal studies.

Quantitative trait loci influencing β-glucan content in oat (Avena sativa, 2n=6x=42)

The β-glucan content of oat grain is of inter-est due to its positive human health role as a dietary component influencing serum cholesterol levels and its relation to the energy intake of livestock feed. Two recombinant inbred populations sharing a common parent (Kanota × Ogle and Kanota × Marion), and containing 137 individual lines each, were used to identify genomic regions that influence the β-glucan content in cultivated oat. Single-factor ANOVA, a backward elimination process, simple interval mapping (SIM) and simplified composite interval mapping (sCIM) were used to identify quantitative trait loci (QTLs). Regions on linkage groups 11 and 14 of the hexaploid oat RFLP map influenced β-glucan levels in both populations and over environments. Other genomic regions were identified whose effects varied depending on the genetic background, but were significant over measurements for a given population. Kanota and Ogle exhibit similar β-glucan levels and each parent contributed about the same number of positive β-glucan alleles in the Kanota × Ogle cross. Marion is higher in β-glucan content than Kanota and contributed all of the positive alleles in the Kanota × Marion cross. Three of the β-glucan QTL regions identified have been previously implicated as having a significant influence on the groat oil content in oat. These correlated QTL regions were either in coupling phase, with a region from one parent having the same effect on both traits, or were in repulsion phase. Identification of coupling- and repulsion-phase QTL regions for β-glucan and oil content facilitates the use of markers in manipulating these traits in oat breeding.

Effect of skim milk supplementation on blood cholesterol concentration, blood pressure, and triglycerides in a free-living human population.

In 82 subjects, aged 21-73, we studied the effect of skim milk supplementation on serum cholesterol concentration, blood pressure, and serum triglyceride level. The study involved a 1-week pretreatment baseline period followed by 8 weeks of milk supplementation. Sixty-four people were designated to a test group and 18 people were placed in a seasonal index group. The study was designed as a free-living trial, i.e., participants were requested to maintain their normal lifestyles, including dietary pattern, except for the supplementation of one quart of 2% solids-not-fat fortified skim milk to the daily diet in the test group. Supplemental milk treatment was associated with a 6.6% reduction (p = 0.0004) of serum cholesterol in the high cholesterol (greater than or equal to 190 mg/dl) test subgroup within the first 4 weeks. No change was noted in serum cholesterol in the low-cholesterol (less than 190 mg/dl) subgroup throughout the study. Body weight and seasonal variation of blood cholesterol did not significantly influence serum cholesterol levels. Reduction (p = 0.0140) in percentage of calories from fat in the high-cholesterol subgroup was not correlated with the decrease in serum cholesterol in this test subgroup. Reductions in systolic and diastolic blood pressure occurred in the test subgroups; the low-cholesterol subgroup had a greater reduction (p = 0.0002) in diastolic blood pressure than the high-cholesterol group (p = 0.0049). Milk supplementation was associated with reduction (p = 0.0370) in serum triglycerides in the high-cholesterol subgroup.

Genetic analysis of the polymorphism of the human apolipoprotein E using automated solid-phase sequencing

A direct sequencing approach has been used to analyze the polymorphism in the human apolipoprotein E gene. A method is described, in which the DNA is amplified by the polymerase chain reaction, immobilized, and sequenced by a semi-automatic procedure adaptable to clinical diagnosis. The three alleles of the apolipoprotein E gene, which differ from each other by two nucleotide substitutions and which influence serum cholesterol levels, were analyzed. The solid-phase method was able to resolve the correct nucleotide sequence in samples from both homozygous and heterozygous individuals. No cloning steps are needed and the immobilization and separation of the DNA is accomplished using magnetic beads.

Serum Cholesterol Levels in Rats Fed Skim Milk Fermented by Lactobacillus Acidophilus

ABSTRACTThe effects of reconstituted skim milk, and the same fermented by Lactobacillus acidophilus, were tested in rats. Rats were fed a stock diet and drinking water containing one of three milk treatments: (1) no supplementary milk; (2) 10% milk; or (3) 10% milk fermented by L. acidophilus. After 4 wk, rats receiving the fermented milk had lower (P &lt; 0.05) serum cholesterol levels (65 mg/dl) than did the water‐fed (78 mg/dl) or milk‐fed (79 mg/dl) rats. Weight gain, feed intake, liver lipid contents and fecal lactobacilli counts were not different among treatment groups. Data indicate that factors influencing serum cholesterol levels were produced during fermentation of the milk.

Dependence of the effects of dietary cholesterol and experimental conditions on serum lipids in man II. Effects of dietary cholesterol in a linoleic acid-poor diet

In this experiment the effect of dietary cholesterol on serum cholesterol levels was tested in a linoleic acid-poor diet. In a cross-over design 34 healthy students received a linoleic acid-poor diet for 6 weeks at two levels of dietary cholesterol for 3 weeks each. The visible fat was supplied in the form of margarine so that the diet contained only 5 energy% linoleic acid. The high-cholesterol diet was obtained by providing two egg yolks a day. During the experimental period an intestinal infection was noticed, based on their diaries, in 16 subjects. Because of the expected influence on serum cholesterol levels all suspected individuals were removed from the records by independent experts and treated separately. Only the results of the 18 healthy persons are discussed in this paper. Supplementation of two eggs a day caused a highly significant (P < 0.01) rise in serum cholesterol levels of 26 ± 20 mg/100 ml (0.65 mmole/liter) in the two experimental groups. After correction for differences in the fat content of the diets an effect of 21 mg (0.54 mmole/liter) remained. As noticed in the first experiment (part 1) the rise in serum cholesterol levels in groups fed a high-cholesterol, high-polyunsaturated fat diet was only 11 mg/100 ml (0.29 mmole/liter). Comparing the two results it is concluded that the effect of dietary cholesterol is clearly dependent on the type of fat present in the diet. Eggs will have a rather important elevating effect in a saturated fat diet, which is the more deleterious as the saturated fat already induces high cholesterol levels. However, linoleic acid-rich fat reduces serum cholesterol levels markedly, while the opposing effect of dietary cholesterol in this case is much smaller. The results of this study emphasize the importance of considering the complexity and interrelations of all constituents of a diet in affecting health parameters. By substituting the type of fat and changing the amount of egg cholesterol, it seems feasible to influence serum cholesterol levels of young healthy men in the range of 145 to 210 mg/100 ml (3.7 to 5.4 mmole/liter).

Relation of hemodynamics to the incidence of diethylstilbestrol-induced aortic ruptures in hypertensive and hypotensive lines of turkeys.

Hypertensive and hypotensive lines of turkeys were treated with diethylstilbestrol (DES) alone, or with DES and propranolol (PROP). Untreated turkeys of each blood pressure line served as controls. Mortality rate from aortic ruptures was highest (43.7%) in the hypertensive line treated with DES, but mortality was reduced to 7.7% when this line of turkey was treated with both DES and PROP. Among the hypotensive line of turkeys treated with DES, 26.7% died of aortic ruptures, but none died when these turkeys were treated with DES and PROP. Propranolol did not influence serum cholesterol levels, and all DES or DES and PROP treated birds had greatly elevated values, as contrasted to untreated turkeys. Aortic lipid values were highest in the hypotensive line of turkeys treated with DES, but, by histologic evaluation, aortic atherosclerosis was equally severe in all DES-treated turkeys. Blood pressure and aortic dp/dt max were higher in the hypertensive line treated with DES than in the similarly treated hypotensive line. This probably accounted for the higher mortality in the former group. Absence of significant mortality in either line of turkey following treatment with both DES and PROP apparently resulted from the decreased stress on the aorta caused by lowering of blood pressure and aortic dp/dt max by PROP.

Factors influencing serum cholesterol levels in swine.

Factors that influence serum cholesterol levels in swine were examined. Body weight and dam had significant influences on the serum cholesterol levels. No effects of age of pig (50-59 days of age), sex, farrow, sire, or litter size on serum cholesterol levels were detected. The heritability of serum cholesterol in swine estimated in this study is about 25 percent. Two generations of selection appear to have produced lines of pigs characterized by serum cholesterol levels that are genetically distinct with an estimate of realized heritability of 0.22.

The effect on rabbit intestinal microflora of diets which influence serum cholesterol levels

The predominant organism in the lower intestine of the rabbit has been characterized and shown to be a Bacteroides sp. Diets which had a marked effect on the plasma cholesterol levels of rabbits failed to produce any detectable changes in the bacteroides population or in any of the other groups of intestinal bacteria examined.

Failure of Dietary Carbohydrates to Influence Tissue Cholesterol in the Adult Male Chicken

The influence of dietary carbohydrates on cholesterol metabolism has been studied in various species. Early reports indicate that the type of dietary carbohydrate tends to influence serum cholesterol levels (Kritchevsky, 1958; Fahrenbach and Grant, 1959). More recent studies, however, show that although the type of dietary carbohydrate may influence serum cholesterol when fed in a hypercholesterolemic diet, it has no effect in a normal low cholesterol diet (Guggenheim et al., 1960; Taylor et al., 1967). Studies with chickens have all been conducted on young growing chicks fed the experimental diets for relatively short periods of time (3–6 weeks). This study, however, was conducted with adult males that were fed the experimental diets for four months.MATERIALS AND METHODSFifty male White Leghorn chicks were fed all mash starter and grower practical type rations and raised in wire cages from one day to four months of age. Thirty of these…

PHYSIOLOGIC FACTORS INFLUENCING CIRCULATING TRIGLYCERIDE CONCENTRATION IN WOMEN: AGE, WEIGHT GAIN, AND OVARIAN FUNCTION.

Abstract Serum triglyceride concentration was measured by direct glycerol determination in 99 women, aged 17 to 90. The arithmetic mean level was 86 mg. per 100 ml. The lognormal mean was 77 mg. per 100 ml. A highly significant increase in circulating triglycerides was observed in women over age 35 compared to younger women (88 mg. and 53 mg. per 100 ml., respectively). Triglyceride levels were significantly higher in women who gained weight (101 mg. per 100 ml.) than in women with stable weight (75 mg. per 100 ml.). Higher triglyceride values in menopausal women (102 mg. per 100 ml.) compared to premenopausal women (75 mg. per 100 ml.) were of borderline statistical significance. Serum cholesterol and phospholipids were significantly higher in older women. Weight gain did not influence serum cholesterol levels. Alterations observed in lipoprotein distribution included a relative decrease in alpha-lipoprotein in women who gained weight. Free fatty acid levels did not vary with age. The most striking alteration in triglyceride concentration was the increment associated with aging. This influence prevailed independently of weight gain or cessation of ovarian function, which also contributed an increase. These observations may be related to the incidence of atherosclerosis.

Failure of parenterally administered pyridoxine to influence serum cholesterol levels and development of atherosclerosis in cholesterol-fed rabbits.

Pyridoxine administered parenterally was found to have no effect on serum cholesterol levels of rabbits fed a normal diet, nor did it inhibit the development of hypercholesterolemia and atherosclerosis in rabbits fed a cholesterol-rich diet.