Rural-to-urban migration and cardiovascular disease risk factors in young Guatemalan adults

BACKGROUND: Migration to cities may increase cardiovascular disease risk factors in developing countries. We examined rural and urban individuals who were born in the same villages and shared similar childhood experiences. METHODS: Blood lipids and glucose, blood pressure, anthropometry, body composition, physical activity, and food, tobacco and alcohol consumption were examined in 161 men and 193 women, 19-29 years old, living in their village of birth (76 commuted to work in Guatemala City), and in 76 men and 43 women living in the city. RESULTS: Rural and urban women had similar prevalence of overweight (28%), elevated body fat (29.8 +/- 6.1%) and low physical activity (83%). Compared to rural men, more urban men were sedentary (79 versus 27%), and they had higher body fat (15.3 +/- 5.3% versus 13.3 +/- 5.7%), serum cholesterol (4.27 +/- 0.75 versus 3.90 +/- 0.70 mmol/l [165 +/- 29 versus 151 +/- 27 mg/dl]), low density lipoprotein [LDL]-cholesterol (2.66 +/- 0.72 versus 2.30 +/- 0.62 mmol/l [103 +/- 28 versus 89 +/- 24 mg/dl]) and total cholesterol/high density lipoprotein [HDL]-cholesterol ratio (4.6 +/- 1.0 versus 4.1 +/- 0.9). Commuters showed intermediate values. Women had higher serum cholesterol (4.43 +/- 0.80 mmol/l [171 +/- 31 mg/dl]) than men in rural and urban areas. Urban residents ate/drank more saturated fats, red meat and sweetened beverages, and less legumes. CONCLUSIONS: High proportions of young Guatemalan women were overweight and sedentary. Migration to a city increased sedentarism and undesirable eating habits among men and women; men became fatter and their lipid profile worsened. Public health actions must address the prevention of emerging chronic diseases in countries still burdened by undernutrition and infections.     

A palm oil-rich diet may reduce serum lipids in healthy young individuals

OBJECTIVE: The literature on palm oil as a cholesterol-raising oil is conflicting, requiring further studies. This study tested the influence of a palm oil-rich diet on plasma lipids of healthy young individuals. METHODS: Thirty-four medical students, 18-26 y old, with a total cholesterol level <200 mg/dL, high-density lipoprotein cholesterol (HDL-C) level >40 mg/dL, low-density lipoprotein cholesterol (LDL-C) level <130 mg/dL, triacylglycerol level <150 mg/dL, glycemic level <100 mg/dL, blood pressure <140/90 mmHg, and a body mass index of 18 to <25 kg/m(2) were studied. Once a day for 2 wk, the students ingested 10 mL of previously boiled crude palm oil after lunch or dinner, as preferred. Palm oil was consumed in the same way and quantity that it is consumed in one serving of a very popular typical Brazilian seafood dish. Total cholesterol, LDL-C, HDL-C, very LDL-C, non-HDL-C, and triacylglycerol were measured at baseline, after the palm oil-enriched diet, and after the washout period. RESULTS: A decrease in all lipid fractions was observed, with a mild, statistically significant decrease in concentrations of very LDL-C (19.41 +/- 4.21 versus 17.18 +/- 4.0 mg/dL, P = 0.002) and triacylglycerol (97.07 +/- 21.08 versus 85.91 +/- 20.02 mg/dL, P = 0.002). Males (61.9%) also showed a mildly significant increase in LDL-C, whereas females showed a mildly significant decrease in all lipid fractions, except for HDL-C. CONCLUSION: This study shows that boiled crude palm oil may have a mild, triacylglycerol-reducing effect in young, healthy individuals and may also show a mild LDL-C-increasing effect in males.     

Dietary medium-chain triacylglycerol prevents the postprandial rise of plasma triacylglycerols but induces hypercholesterolemia in primary hypertriglyceridemic subjects

BACKGROUND: Previous studies showed divergent results concerning the influence of medium-chain triacylglycerol (MCT) on lipoprotein metabolism. OBJECTIVE: The objective of this study was to compare the effects of MCT and corn oil on plasma lipids in primary hypertriglyceridemic patients. DESIGN: Ten subjects ate different proportions of corn oil and MCT for 12 wk. The subjects first ate a low-fat diet for 2 wk and during the next 4 wk, corn oil was added as the sole source of fat. Thereafter, for 2-wk periods, the subjects were sequentially fed corn oil and MCT mixed in the following proportions: 3:1, 1:1, and 0:1. Fasting plasma total cholesterol, triacylglycerol, and HDL-cholesterol concentrations were measured at the end of each period. At the end of the 100%-corn oil and of the 100%-MCT periods, subjects were fed a test meal containing the respective oil (40 g fat/m(2) body surface area) and total cholesterol and triacylglycerols were measured at 2-h intervals over 8 h; fasting lipoprotein composition was also measured. RESULTS: Compared with corn oil, MCT was associated with a higher mean (+/-SD) fasting total cholesterol concentration (6.39 +/- 1.14 compared with 5.51 +/- 0.98 mmol/L, respectively; P < 0. 05); non-HDL-cholesterol concentrations were also higher with MCT (5. 36 +/- 1.11 mmol/L) than with corn oil (4.51 +/- 0.92 mmol/L; P < 0. 005). In response to the liquid test meal, plasma total cholesterol did not change with either diet but triacylglycerols increased with the 100%-corn oil diet. CONCLUSIONS: MCT prevents the risk of pancreatitis due to postprandial hypertriglyceridemia but has the inconvenience of raising total cholesterol concentrations in primary hypertriglyceridemic subjects.     

Effect of alcohol on postprandial lipemia with and without preprandial exercise

OBJECTIVE: Different factors such as exercise habits and alcohol consumption may modulate postprandial lipid metabolism. What are the effects of alcohol on postprandial metabolism in untrained and trained individuals? METHODS: The postprandial lipid response to an oral fat load (1 g fat per kg body weight (bw)) with and without alcohol (0.5 g/kg bw) was evaluated in physically trained healthy young men (T, n = 12, mean +/- SD age 27 +/- 3 years. BMI 21.6 +/- 1.4 kg/m2) after a premeal running session and in untrained healthy young men (UT, n = 8, age 24 +/- 1 years, BMI 23.2 +/- 1.8 kg/m2) without a premeal exercise session. The T subjects ingested 35.5 +/- 2.7 g alcohol, the UT subjects 38 +/- 0.6 g. Fat was given as butter and the carbohydrates as marmalade and zwieback (rusk). The T subjects received 1.20 +/- 0.05 g fat and 1.02 +/- 0.04 g carbohydrates per kilogram lean body mass. The corresponding numbers for the UT subjects were 1.28 +/- 0.08 g and 1.20 +/- 0.06 g. The postprandial lipemia was observed for an eight-hour period. RESULTS: Alcohol led to an increase to the triacylglycerol area under the curve (AUC) in the T subjects from 7.4 +/- 0.4 mmol/L * h on the control day to 11.3 +/- 0.9 mmol/L * h (p = 0.001). The corresponding numbers in the UT subjects were 13.4 +/- 2.3 mmol/L * h to 19.4 +/- 3.5 mmol/L * h (p = 0.004). Alcohol intake and physical activity training were the major determinants of the triacylglycerol (TG) AUC in these subjects. CONCLUSION: The ingestion of a high fat meal in combination with alcohol leads to an increased in the postprandial lipemia independently from the level of training. It is suggested that this unfavorable effect of alcohol and a high fat diet could be modified by fat restriction or a combination of a premeal exercise session and a higher level of physical activity training.     

Much lower prevalence of coronary calcium detected by electron-beam computed tomography among men aged 40-49 in Japan than in the US, despite a less favorable profile of major risk factors

BACKGROUND: Since World War II (WWII), exposures to westernized lifestyle have occurred in many non-Western countries, including Japan. National surveys showed that risk factor profiles for atherosclerosis around 1990 were similar in men in the post WWII birth cohorts in the US and Japan. We compared the degree of coronary calcium and other factors in men in the post WWII birth cohort: men aged 40-49 in the US and Japan. METHODS: We conducted a cross-sectional study examining randomly selected 100 men from Kusatsu, Japan, and 100 men from Allegheny County, US. Coronary calcium was assessed using electron-beam computed tomography. RESULTS: Systolic blood pressure, total cholesterol, low density lipoprotein (LDL)-cholesterol, and smoking rates were higher among the Japanese (122.6 +/- 14.1 versus 113.7 +/- 9.6 mmHg, P < 0.01; 5.72 +/- 0.90 versus 4.99 +/- 0.81 mmol/l (220.9 +/- 34.6 versus 192.8 +/- 31.3 mg/dl), P < 0.01; 3.52 +/- 1.01 versus 3.10 +/- 0.78 mmol/l (136.0 +/- 39.0 versus 119.7 +/- 30.0 mg/dl), P < 0.01; and 48 versus 15%, P < 0.01, respectively). Triglycerides and fibrinogen were similar. High density lipoprotein (HDL)-cholesterol was higher among the Japanese. Body mass index, fasting insulin, and C-reactive protein were higher among the Americans. Prevalence of coronary artery calcium score >0 was strikingly lower among the Japanese than the Americans (13% versus 47%, P < 0.01). CONCLUSIONS: Much lower prevalence of coronary calcium despite a less favourable profile of many major independent risk factors in the Japanese might imply that there are strong protective factors against atherosclerosis in the Japanese. Further investigation is of critical importance.     

Behenic acid is a cholesterol-raising saturated fatty acid in humans

BACKGROUND: Dietary behenic acid (22:0) is poorly absorbed. Because of its low bioavailability compared with other fatty acids and because of its very long chain length, the effect of dietary behenic acid (behenate) on serum lipid concentrations in humans is assumed to be neutral. OBJECTIVE: The objective was to establish the cholesterol-raising potential of behenic acid by comparing the effects on lipid and lipoprotein concentrations of a specially formulated fat enriched with behenic acid with those of palm oil (rich in palmitic acid; 16:0) and high-oleic acid sunflower oil (rich in cis oleic acid; 18:1). DESIGN: In a randomized, crossover, metabolic-ward study, 7 mildly hypercholesterolemic men were fed 3 natural-food diets supplemented with behenate oil, palm oil, or high-oleic acid sunflower oil. Mean serum lipid and lipoprotein concentrations and plasma triacylglycerol fatty acid composition were determined from fasting blood drawn during the final 4 d of each 3-wk diet period. RESULTS: Behenate oil produced mean concentrations of total cholesterol (5.87+/-0.8 mmol/L) and LDL cholesterol (4.40+/-0.8 mmol/L) not significantly different from those produced by palm oil (5.84+/-0.7 and 4.42+/-0.7 mmol/L, respectively) but significantly higher than those produced by high-oleic acid sunflower oil (5.12+/-0.5 and 3.70+/-0.6 mmol/L, respectively). There were no significant differences in triacylglycerol or HDL-cholesterol concentrations. CONCLUSIONS: Despite its low bioavailability compared with oleic acid, behenic acid is a cholesterol-raising fatty acid in humans and is therefore not a suitable substitute for palmitic acid in manufactured triacylglycerols.     

High-carbohydrate, high-fiber diets increase peripheral insulin sensitivity in healthy young and old adults

To examine extra-alimentary effects of high-carbohydrate, high-fiber (HCF) diets, insulin-mediated glucose disposal employing the euglycemic clamp and hepatic glucose output (HGO) employing [6,6-2H2]glucose were measured in 12 healthy young and old individuals before and after 21-28 d of an HCF diet. Diet lowered fasting concentrations of glucose from 5.3 +/- 0.2 to 5.1 +/- 0.1 mmol/L (p less than 0.01) and insulin from 66.0 +/- 7.9 to 49.5 +/- 5.7 pmol/L (p less than 0.01). Fasting serum cholesterol decreased from 5.17 +/- 0.18 to 3.80 +/- 0.20 mmol/L (p less than 0.01) in young individuals and from 6.15 +/- 0.52 to 4.99 +/- 0.49 mmol/L (p less than 0.01) in elderly individuals. Fasting serum triglyceride concentrations, basal HGO, and insulin suppression of HGO were unchanged by the diet. Glucose disposal rates increased from 18.87 +/- 1.66 before 23.87 +/- 2.78 mumol.kg-1.min-1 after the diet (p less than 0.02). Therefore, HCF diets may improve carbohydrate economy by enhanced peripheral sensitivity to insulin.     

Changes in plasma lipoproteins during low-fat, high-carbohydrate diets: effects of energy intake

BACKGROUND: Low-fat diets can increase plasma triacylglycerol and reduce HDL cholesterol. Changes in energy intake and body weight can influence the lipoprotein response. OBJECTIVE: We sought to prospectively examine the effects of euenergetic and ad libitum dietary fat restriction on plasma lipoproteins in healthy postmenopausal women. DESIGN: Participants first received a controlled euenergetic diet in which dietary fat was reduced stepwise from 35% to 25% to 15% over 4 mo. Thereafter, participants followed an ad libitum 15%-fat diet for 8 mo; 54 women completed the intervention. RESULTS: During the controlled euenergetic diet, plasma triacylglycerol increased from 1.70 +/- 0.10 to 2.30 +/- 0.16 mmol/L, total cholesterol decreased from 5.87 +/- 0.13 to 5.53 +/- 0. 13 mmol/L, LDL cholesterol decreased from 3.41 +/- 0.10 to 2.87 +/- 0.10 mmol/L, HDL cholesterol decreased from 1.76 +/- 0.08 to 1.50 +/- 0.08 mmol/L, and apolipoprotein (apo) A-I decreased from 5.11 +/- 0.14 to 4.78 +/- 0.14 mmol/L (P < 0.0001 for all changes). Hormone replacement therapy did not affect the relative change in HDL cholesterol. Plasma glucose, insulin, hemoglobin A(1C,) free fatty acid, and apo B concentrations did not change significantly. During the ad libitum 15%-fat diet, participants lost 4.6 +/- 0.4 kg. Plasma triacylglycerol and LDL cholesterol returned to baseline values (1.77 +/- 0.12 and 3.31 +/- 0.08 mmol/L, respectively), whereas HDL cholesterol and apo A-I remained low (1.40 +/- 0.08 and 4.82 +/- 0.18 mmol/L, respectively). HDL cholesterol and apo A-I concentrations stabilized in subjects who were not receiving hormone replacement therapy but continued to decline in women who were receiving hormone therapy. CONCLUSIONS: The ad libitum 15%-fat diet resulted in significant weight loss. The euenergetic but not the ad libitum diet caused hypertriacylglycerolemia. HDL cholesterol decreased during both low-fat diets.     

Wheat-bran and oat-bran supplements' effects on blood lipids and lipoproteins.

To compare the effects of oat-bran fiber on blood lipids, we studied 84 healthy middle-aged men and women who were placed on metabolic diets, for 2 wk, that were supplemented with either wheat bran (n = 42) or oat bran (n = 42). Fiber supplementation was 1.6 micrograms dietary fiber/J (6.8 g dietary fiber/1000 kcal) to a maximum of 16.4 g fiber/d. Significantly greater decrease with oat than with wheat were seen in total cholesterol (0.56 +/- 0.08 mmol/L and 0.29 +/- 0.08 mmol/L, P = 0.022) and low-density-lipoprotein cholesterol (0.39 +/- 0.07 mmol/L and 0.15 +/- 0.07 mmol/L, P = 0.024). No significant differences were seen in high-density lipoprotein, apolipoproteins A-1 and B, or triglyceride. We conclude that oat bran has an advantage over wheat bran in lowering serum lipids when tested in metabolic diets on large numbers of individuals with an initial mean serum cholesterol concentration above the desirable range, at 5.61 +/- 0.16 mmol/L.     

Dairy fat in cheese raises LDL cholesterol less than that in butter in mildly hypercholesterolaemic subjects

OBJECTIVE: To determine whether dairy fat in cheese raises low-density lipoprotein (LDL) cholesterol as much as in butter, since epidemiology suggests a different impact on cardiovascular disease. DESIGN: A randomised crossover trial testing the daily consumption of 40 g dairy fat as butter or as matured cheddar cheese, each of 4 weeks duration, was preceded by and separated by 2-week periods when dietary fat was less saturated. SETTING: Free-living volunteers. SUBJECTS: A total of 14 men and five women of mean age 56+/-8 y, with mean total cholesterol of 5.6+/-0.8 mmol/l. MAIN OUTCOME MEASURES: Plasma cholesterol, LDL cholesterol (LDL-C), HDL cholesterol (HDL-C), triacylglycerol and glucose. RESULTS: Saturated fat intake was significantly lower during the run-in than during the cheese and butter periods. Mean lipid values did not differ significantly between the cheese and run-in periods, but total cholesterol and LDL-C were significantly higher with butter: total cholesterol (mmol/l): butter 6.1+/-0.7; run-in 5.6+/-0.8 (P < 0.05; ANOVA with Bonferroni adjustment); vs cheese 5.8+/-0.6 (P > 0.05); median LDL-C (mmol/l): butter 3.9 (3.5-4.1) vs run-in 3.4 (3.0-4.1) (P < 0.05; Tukey test); vs cheese 3.7 (3.3-3.9) (P > 0.05). Among 13 subjects whose initial LDL-C was >4 mmol/l, the difference between butter (4.4+/-0.3 mmol/l) and cheese (3.9+/-0.3 mmol/l) was significant (P = 0.014). HDL-C was highest with butter and triacylglycerol with cheese (neither was significant). CONCLUSION: A total of 40 g dairy fat eaten daily for 4 weeks as butter, but not as cheese, raised total and LDL cholesterol significantly compared with a diet containing significantly less saturated fat. Dietary advice regarding cheese consumption may require modification.     

Effects of soy protein supplemented with methionine on blood lipids and adiposity of rats

OBJECTIVE: The effects of soy protein isolate (SPI) versus casein on blood lipids and adiposity were investigated in rats fed methionine-equivalent diets. METHODS: Twenty-eight male Sprague-Dawley rats (230 to 250 g) were assigned in equal numbers to groups consuming SPI- or casein-based diets (20%) supplemented with L-methionine. After 28 d, blood was collected for triacylglycerol, total cholesterol, and high-density lipoprotein cholesterol assessment and epididymal fat pads were weighed. RESULTS: Food intake (519 +/- 90 versus 490 +/- 115 g), weight gain (144 +/- 35 versus 133 +/- 28 g), food efficiency ratio (0.29 +/- 0.09 versus 0.28 +/- 0.06), epididymal fat pad weights (5.409 +/- 2.076 versus 4.768 +/- 1.867 g), and serum concentrations of triacylglycerol (96.3 +/- 41.8 versus 93.4 +/- 37.4 mg/dL) and high-density lipoprotein cholesterol (32.6 +/- 7.4 versus 33.8 +/- 4.4 mg/dL) were similar between the casein and SPI groups, respectively. However, total cholesterol (73.8 +/- 17.8 versus 59.3 +/- 11.9 mg/dL) concentration was higher for the casein-fed rats than for the SPI-fed rats, respectively (P < 0.05). CONCLUSIONS: These results suggest that methionine supplementation may eliminate the decreased fat deposition previously ascribed to soy protein; however, methionine did not abolish the commonly observed hypocholesterolemic effects of soy.     

Whole-body fat oxidation rate and plasma triacylglycerol concentrations in men consuming an ad libitum high-carbohydrate or low-carbohydrate diet

BACKGROUND: High-carbohydrate diets may increase plasma triacylglycerol concentrations either by increasing production of triacylglycerols or by reducing their clearance. OBJECTIVE: We assessed whether the changes in plasma triacylglycerol concentrations induced by dietary interventions were associated with the changes in whole-body fat oxidation rates. DESIGN: In a parallel study, 37 healthy male subjects [body mass index (in kg/m(2)): 28 +/- 5, age: 34 +/- 11 y (x +/- SD)] consumed an ad libitum high-carbohydrate (60% of energy; n = 19) or low-carbohydrate (46% of energy), high-fat (41% of energy, 23% as monounsaturated fatty acids; n = 18) diet for 7 wk. The following variables were measured before and after the dietary interventions: 1) plasma triacylglycerols before and 2, 4, 6, and 8 h after a meal (containing 40% of daily energy needs and 41% fat); 2) indirect calorimetry throughout the 8-h test; and 3) postheparin plasma lipoprotein lipase (phLPL) activity at time 8 h of the test. RESULTS: The diets induced changes in 1) body weight: -2.5 +/- 2.8 kg (P < 0.01) and -1.7 +/- 3.1 kg (P < 0.05) and 2) fasting plasma triacylglycerols: 0.0 +/- 0.4 mmol/L (NS) and -0.3 +/- 0.3 mmol/L (P < 0.05) for the high-carbohydrate and the low-carbohydrate diets, respectively. In normoinsulinemic subjects (fasting insulin < 100 pmol/L), dietary changes in postprandial triacylglycerols were significantly predicted by changes in phLPL, body weight, respiratory quotient (or fat oxidation), and the type of diet (stepwise multiple linear regression). CONCLUSION: Postprandial plasma triacylglycerol concentrations may depend at least partly on fat oxidation, body weight, and LPL activity.     

Concentrated pomegranate juice improves lipid profiles in diabetic patients with hyperlipidemia

This study assessed the effect of concentrated pomegranate juice (CPJ) consumption on lipid profiles of type II diabetic patients with hyperlipidemia (cholesterol >/= 5.2 mmol/L or triacylglycerol >/= 2.3 mmol/L). In this quasi-experimental study 22 otherwise healthy diabetic patients, 14 women (63.6%) and eight men (36.4%), were recruited from among patients referred to the Iranian Diabetes Society. The patients were followed for 8 weeks to establish a baseline for normal dietary intake before beginning the CPJ intervention. During the pre-study period a 24-hour food recall and food records (recording flavonoid-rich foods) were completed every 10 days. At the end of the eighth week, anthropometric and biochemical assessments were done. Thereafter the patients consumed 40 g/day of CPJ for 8 weeks, during which time dietary assessment was continued. After completing the study, anthropometric and blood indices were again evaluated. The Wilcoxon signed test was used for statistical analysis. A value of P <.05 was considered significant. Mean (+/-SD) age, weight, and duration of diabetes were 52.5 +/- 5.2 years, 71.5 +/- 10.3 kg, and 7.9 +/- 6.6 years, respectively. After consumption of CPJ, significant reductions were seen in total cholesterol (P <.006), low-density lipoprotein (LDL)-cholesterol (P <.006), LDL-cholesterol/high-density lipoprotein (HDL)-cholesterol (P <.001), and total cholesterol/HDL-cholesterol (P <.001). But, there were no significant changes in serum triacylglycerol and HDL-cholesterol concentrations. Anthropometric indices, physical activity, kind and doses of oral hypoglycemic agents, and the intakes of nutrients and flavonoid-rich foods showed no change during the CPJ consumption period. It is concluded that CPJ consumption may modify heart disease risk factors in hyperlipidemic patients, and its inclusion therefore in their diets may be beneficial.     

Effect of a high-carbohydrate vs a high–cis-monounsaturated fat diet on lipid and lipoproteins in individuals with and without type 2 diabetes

It is not known whether the extent of the improvement in lipids and lipoproteins on a high–cis-monounsaturated (high-mono) diet compared with a high-carbohydrate (high-carb) diet is different in patients with type 2 diabetes mellitus (T2DM) and nondiabetic subjects. The aim of this study is to compare the effect of a high-mono and a high-carb diet on lipids and lipoproteins in patients with T2DM and nondiabetic subjects.

Ten healthy nondiabetic men, 8 men with T2DM on dietary therapy alone, and 10 men with T2DM requiring insulin therapy were fed an isoenergic high-carb diet (60% energy as carbohydrate and 25% as fat) and a high-mono diet (50% energy as fat and 35% as carbohydrate) for 2 to 4 weeks in a randomized, crossover fashion. Dietary fiber, simple carbohydrates, and cholesterol were held constant across diets. The lipid and lipoprotein responses to these diets were compared in nondiabetic and T2DM subjects by repeated measures analysis of variance model. Patients with T2DM had 2.2 to 2.3 times greater reductions in plasma triacylglycerol, very low-density lipoprotein (VLDL) cholesterol, and total cholesterol/high-density lipoprotein cholesterol ratio (TC/HDLC) on the high-mono diet compared with the high-carb diet than the nondiabetic subjects (P = .02-.04). The reductions in triacylglycerol and VLDL cholesterol were 2.7 times greater (P = .009-.02) in T2DM subjects with high plasma triacylglycerol concentrations (>2.26 mmol/L) but only 1.4 to 2.0 times greater (P = .16-.52) in T2DM patients with low triacylglycerol concentrations (<2.26 mmol/L) compared with nondiabetic subjects who all had low triacylglycerol concentrations (<2.26 mmol/L). Patients with T2DM experienced greater decreases in plasma triacylglycerol, VLDL cholesterol, and TC/HDLC on a high-mono diet compared with a high-carb diet than nondiabetic subjects. The extents of the improvements were likely related to plasma triacylglycerol concentrations in patients with T2DM.     

Pharmacokinetics of quinine in young and elderly subjects.

The effect of age on the pharmacokinetics of quinine was investigated by comparing its kinetic behaviour in 12 young healthy adults and 8 healthy elderly subjects after a single 600 mg oral dose of quinine sulphate. Peak plasma quinine concentration and the time of peak concentration were similar in the young and elderly subjects. The mean oral clearance of quinine was found to be significantly decreased in the elderly (P less than 0.05, 0.062 litre/h/kg vs 0.084 litre/h/kg) as compared to the young. This was accompanied by a significant increase in the mean elimination half-life of quinine in the elderly group (18.4 +/- 5.7 [standard deviation] h vs 10.5 +/- 1.6 h, P less than 0.05). There was no significant difference in the renal clearance of quinine between the young and the elderly (P greater than 0.05). However, elderly subjects excreted 16.6 +/- 3.7% of the dose as unchanged quinine in the urine and this was significantly greater (P less than 0.005) than the amount excreted by the young (11.2 +/- 2.5%). The results of this study indicate that the elimination processes for quinine are impaired in normal elderly subjects. The clinical significance of these findings is unknown, but they indicate the need for caution in the administration of quinine to elderly patients.     

Effect of 6 dietary fatty acids on the postprandial lipid profile, plasma fatty acids, lipoprotein lipase, and cholesterol ester transfer activities in healthy young men

BACKGROUND: There is increasing evidence that postprandial triacylglycerol-rich lipoproteins may be related to atherogenic risk. OBJECTIVE: The objective was to investigate the effect of individual fatty acid intakes on postprandial plasma lipoprotein triacylglycerol and cholesterol concentrations, plasma fatty acids, and preheparin lipoprotein lipase and cholesterol ester transfer protein (CETP) activities. DESIGN: Six test fats high (approximately 43% by wt) in stearic acid, palmitic acid, palmitic + myristic acid, oleic acid, elaidic acid (trans 18:1), and linoleic acid were produced by interesterification. After having fasted for 12 h, 16 healthy young men were served the individual test fats incorporated into meals (1 g fat/kg body wt) in random order on different days separated by washout periods. Blood samples were drawn before and 2, 4, 6, and 8 h after the meals. RESULTS: Different responses to the test-fat meals were observed for plasma lipoprotein triacylglycerol and cholesterol concentrations, plasma fatty acid concentrations, and lipoprotein lipase and CETP activities (diet x time interaction: 0.001 < P < 0.05). Intake of the long-chain saturated fatty acids stearic and palmitic acids resulted in a relatively lower lipemic response than did intake of the unsaturated fatty acids, probably because the saturated fatty acids were absorbed less and at a lower rate; therefore, the lipemic response took longer to return to postabsorptive values. CONCLUSIONS: Fatty acid chain length and degree of saturation appear to affect the extent and duration of lipemia and affect hepatic output indirectly. These effects may not be mediated via effects on lipoprotein lipase and CETP activities.     

Dietary echium oil increases plasma and neutrophil long-chain (n-3) fatty acids and lowers serum triacylglycerols in hypertriglyceridemic humans

A wealth of evidence indicates that consumption of fish or dietary fish oils containing long-chain (n-3) PUFA such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is associated with cardiovascular benefit, including a reduction in circulating triacylglycerol concentrations and reduced mortality from coronary heart disease. Shorter-chain dietary (n-3) PUFA such as alpha-linolenic acid from vegetable oils are inefficiently converted to EPA and DHA and do not possess the hypotriglyceridemic properties attributed to fish oils. The objective of this study was to investigate the effect of dietary Echium oil, a plant oil containing the 18-carbon (n-3) PUFA stearidonic acid, on tissue fatty acid content and serum triacylglycerol concentrations in hypertriglyceridemic humans. Asymptomatic subjects with mild-to-moderate hypertriglyceridemia were enrolled in an open-labeled study. Subjects underwent a 4-wk lead-in period and were then instructed to follow the National Cholesterol Education Program Step 1 diet. Subjects (n = 11) whose serum triacylglycerol concentrations remained between 3.4 and 5.1 mmol/L (300 and 450 mg/dL) were instructed to consume 15 g of Echium oil daily for 4 wk. During the treatment period, serum triacylglycerol concentrations decreased by 21%, or 0.87 +/- 0.26 mmol/L (mean +/- SD) compared with baseline (P < 0.05); 8 of 11 subjects had a decrease in serum triacylglycerols ranging from 13 to 52% with a decrease from baseline of 30%, or 1.26 +/- 0.41 mmol/L (mean +/- SD). There were no significant changes in any other clinical laboratory variables. Concentrations of long-chain (n-3) PUFA, including EPA, increased (P < 0.05) in plasma and neutrophils when subjects consumed Echium oil. In conclusion, dietary plant oils rich in stearidonic acid are metabolized to longer-chain, more unsaturated (n-3) PUFA. These oils appear to possess hypotriglyceridemic properties typically associated with fish oils.     

A mixed Australian fish diet and fish-oil supplementation: impact on the plasma lipid profile of healthy men

Twelve healthy men were fed in turn three diets for 6 wk each in a 3 x 3 randomized block design: a control diet (essentially fish free), a fish diet (200 g lean Australian fish flesh/d), and the same fish-based meal but supplemented with 5 g fish oil/d. Dietary eicosapentaenoic acid [EPA, 20: 5n-3 (omega-3)] was strongly associated with erythrocyte membrane EPA (r = 0.908 at 6 wk), strengthening its value as a measure of compliance in fish and fish-oil feeding trials. On the fish diet, subjects had increased incorporation of n-3 polyunsaturated fatty acids (PUFAs) at the expense of n-6 PUFAs in their erythrocyte membranes. When the fish-based diet was supplemented with fish oil (5 g/d), there was a significant lowering of plasma triacylglycerol (-0.16 +/- 0.24 mmol/L; mean +/- SD). No change in plasma total cholesterol was detected although the fish + oil diet produced a reduction in very-low-density-lipoprotein cholesterol (-0.24 +/- 0.26 mmol/L).     

Gender influence on plasma triacylglycerol response to meals with different monounsaturated and saturated fatty acid content

OBJECTIVE: Both gender and meal fatty acid composition modulate postprandial triacylglycerol (TAG) metabolism, but little information exists on their interaction. We compared postprandial TAG concentrations in men and women after test meals differing in the proportion of monounsaturated (MUFA) and saturated fatty acids (SFA). SUBJECTS: Nine men (body mass index, BMI: 24.5+/-2.3 kg/m(2)) (mean+/-s.d.) and 10 premenopausal women (BMI: 21.2+/-1.7 kg/m(2)), young and healthy, habituated to a relatively high MUFA diet. DESIGN: Plasma responses were studied after subjects consumed two meals, each providing 60 g of fat and 4.7 MJ, on different occasions: one meal was rich in MUFA (MUFA meal: 40 g MUFA; 12 g SFA) and the other meal was rich in SFA (SFA meal: 20 g MUFA; 32 g SFA). The total body and abdominal fat mass were assessed by dual energy X-ray absorptiometry. RESULTS: Fasting plasma TAG concentration did not differ between meals or genders. No gender differences were observed in either total body or abdominal fat mass. The area under the plasma concentration vs time curve was on average 60% higher (P<0.001) in men than women. Repeated measures ANOVA showed a significant effect of meal x time interaction in men (P<0.001) but not in women (P=0.84). In men, maximal plasma TAG occurred at 4 h and was significantly greater after the MUFA meal (2.10+/-0.20 mmol/l) (mean+/-s.e.m.) than after the SFA meal (1.66+/-0.19 mmol/l) (P=0.01). TAG concentration at 5 h was also significantly greater after the MUFA meal. In women, the patterns of TAG responses were identical after the MUFA and SFA meals. CONCLUSIONS: This study provides evidence that gender influences postprandial TAG concentrations when meal fatty acid composition is altered.     

Effect of age on substrate oxidation during total parenteral nutrition

OBJECTIVE: Parenteral nutrition is increasingly used in the elderly. Aging is accompanied by metabolic changes that can modify substrate use. We compared substrate oxidation during cyclic total parenteral nutrition (TPN) in elderly and middle-aged patients. METHODS: Twelve elderly patients (eight women, four men; 72 +/- 5 y) and 12 middle-aged patients (nine women, three men; 39 +/- 13 y) who were on cyclic TPN for intestinal failure were investigated while in stable condition after at least 15 d of TPN. No patient was diabetic. Indirect calorimetry was performed during fasting and every 30 min during the 3 h of TPN infusion and 3 h after infusion, allowing the measurement of nutrient oxidation. Blood samples were obtained every hour for the measurement of glucose, insulin, triacylglycerols, and free fatty acids. RESULTS: In the fasting state, resting energy expenditure was significantly higher in the elderly patients than in the middle-aged patients (39.3 +/- 8.1 versus 31.9 +/- 4.3 kcal/kg of fat-free mass per day, P = 0.008). During TPN, lipid oxidation was significantly higher in the elderly patients than in the middle-aged patients (1.09 +/- 0.17 versus 0.84 +/- 0.27 mg x kg(-1) x min(-1), P = 0.011); glucose oxidation was significantly lower in the elderly patients than in the middle-aged patients (2.19 +/- 0.93 versus 3.22 +/- 1.54 mg x kg(-1) x min(-1), P = 0.038). Areas under the curves of glycemia and free fatty acids were significantly higher in the elderly patients. CONCLUSION: In the elderly, TPN was associated with significantly higher lipid oxidation and lower glucose oxidation than in younger patients. TPN formulas and flow rates should therefore be adapted in the elderly.