Alphalipoprotein cholesterol levels in relation to acute myocardial infarction and its risk factors

Obesity, smoking and secular trends in cardiovascular risk factors in middle-aged women: data from population studies in Göteborg from 1980 to 2003

BACKGROUND

To study the trends in cardiovascular risk factors in middle-aged city-dwelling Swedish women from 1980 to 2003.

METHODS

Using cross-sectional population-based surveys, five random population samples of a total of 1915 women aged between 45 and 54 years, participating in the BEDA study in 1980, WHO MONICA studies in 1985, 1990 and 1995, and a study of 50-year-old women in 2003 were measured for the following parameters: anthropometry, serum cholesterol and triglyceride levels, smoking habits, blood pressure, physical activity and stress.

RESULTS

Over almost 25 years, middle-aged women gained on average 4.4 kg in weight, with a net increase in body mass index (BMI) from 24.7 to 25.6 kg m⁻². The proportion of participants classified as obese (≥30 kg m⁻²) increased by 50% from 10.4% to 15.1%. Women who were smokers in 2003 did not have lower BMI values than nonsmokers. Mean serum cholesterol concentrations decreased markedly, whereas smoking habits did not significantly change. The prevalence of hypertension decreased by 8%, whereas that of diabetes remained stable at around 2%. Optimal risk factor status - no smoking, normotension and serum cholesterol <5 mmol l⁻¹ - was present in less than one in six women in 2003, and similar across BMI categories.

CONCLUSION

The favourable decline in cholesterol levels and hypertension and the increase in leisure time physical activity were offset by an increase in obesity, triglyceride levels and experience of stress, with only a minority of participants (less than one in six) having an optimal level of risk factors with respect to smoking, serum cholesterol and hypertension in 2003. This applied also to overweight and obese women. In earlier cohorts, subjects with low BMI values were more often smokers, whereas the opposite is observed in recent cohorts. Thus, women who smoke no longer have the advantage of lower weight.

Obesity and trends in cardiovascular risk factors over 40 years in Swedish men aged 50

OBJECTIVE

To study trends over 40 years in cardiovascular risk factors in normal weight, overweight and obese men, all aged 50 when examined. Design. Cross-sectional studies of five successive cohorts of men aged 50.

SETTING

City of Göteborg, Sweden.

SUBJECTS

Random population samples of altogether 3251 urban Swedish men born in 1913, 1923, 1933, 1943 and 1953.

MAIN OUTCOME MEASURES

Anthropometry, cardiovascular risk factors, rates of nonsmoking, normotension and serum cholesterol <5 mmol L(-1) over four decades.

RESULTS

Over 40 years, there was a net increase in body mass index (BMI) from 24.8 (SD = 3.2) to 26.4 (3.7) kg m(-2) (P < 0.0001), with an increase in the prevalence of obesity (BMI >or= 30 kg m(-2)) from 6.0% in 1963 to 13.8% in 2003. Favourable trends with respect to smoking, blood pressure and serum cholesterol were observed similarly amongst normal weight, overweight and obese men. In 1963, 24% of obese men were normotensive compared to 45% in 2003, and 6% had serum cholesterol <5 mmol L(-1) compared to 34% in 2003. Compared with obese men in 1963, men who were obese in 2003 had an odds ratio (OR) of 3.39 being a nonsmoker [95% confidence interval (CI): 1.56 to 7.36], 2.67 of being normotensive (1.23 to 5.83) and having serum cholesterol <5 mmol L(-1) of 8.30 (2.37 to 29.0). However, optimal risk factor status - no smoking, normotension and total serum cholesterol <5 mmol L(-1)- was still present in less than one in six men in 2003, similar across BMI categories.

CONCLUSIONS

Obese Swedish men who are now in their fifties have much lower levels of other risk factors compared with obese men 40 years ago. This could contribute to explain why coronary heart disease death rates still are falling despite increasing rates of obesity.

Baseline characteristics and the effects of two years of growth hormone (GH) replacement therapy in adults with GH deficiency previously treated for acromegaly

CONTEXT

The effects of GH replacement in GH-deficient (GHD) adults previously treated for acromegaly are not well known. OBJECTIVE, DESIGN, AND PATIENTS: In this single-center, open-labeled, prospective study, 10 consecutive GHD adults with cured acromegaly (A group) and 10 matched GHD adults with previous nonfunctioning hypopituitary disease (NF group) were included. Comparisons were made at baseline and in the responses in body composition, muscle strength, bone mass, and metabolic indices during 2 yr of GH replacement.

RESULTS

At baseline, upper leg local muscle endurance and serum low-density lipoprotein-cholesterol concentration were more impaired in the A group. The A group contained three patients with hypertension, one with diabetes mellitus type 2, and one with hyperlipidemia. The NF group had only one patient with hypertension. There were no significant between-group differences in the responses to the GH therapy. Body composition and serum lipid pattern improved in both groups without any deterioration of glucose homeostasis. At study end, no difference remained between the two groups in any variable. During the 2-yr treatment, one patient had a myocardial infarction and two had cerebral infarctions in the A group, whereas no vascular event occurred in the NF group.

CONCLUSIONS

GHD patients with previous acromegaly have an impaired cardiovascular risk profile and decreased local muscle endurance as compared with other GHD patients. Two-year GH replacement eliminated these differences, but vascular events occurred more frequently in the A group. Therefore, GHD patients with cured acromegaly will benefit from GH replacement, but careful monitoring of cardiovascular status is needed.

Baseline characteristics and effects of growth hormone therapy over two years in younger and elderly adults with adult onset GH deficiency

CONTEXT

The effects of GH replacement in elderly GH-deficient (GHD) adults are not well known.

OBJECTIVE/DESIGN/PATIENTS

In this prospective, single-center, open-label study, baseline characteristics and the effects of 2-yr GH replacement were determined in 24 GHD adults above 65 yr of age and in 24 younger GHD patients (mean age, 37 yr; range, 27-46 yr). All patients had adult onset disease, and both groups were comparable in terms of the number of pituitary hormonal deficiencies, gender, body mass index, and waist/hip ratio. Duration of hypopituitarism was, however, longer in the elderly patients.

RESULTS

The mean maintenance dose of GH was 0.31 (sem, 0.03) mg/d in the elderly GHD patients and 0.44 (0.04) mg/d in the younger patients. The less marked response in IGF-I sd score, total body fat, and extracellular water in the elderly patients lost significance when the dose of GH was accounted for in the statistical analyses. Despite the lower dose in the elderly GHD group, these patients had a more marked reduction in waist/hip ratio and serum low-density lipoprotein-cholesterol level, and these differences remained also after correction for duration of hypopituitarism. There was no difference at baseline or in responsiveness in lean mass, bone mineral density, and glucose homeostasis.

CONCLUSIONS

This study identifies elderly GHD adults as a GH-sensitive group in whom a low dose of GH can improve body composition and serum lipid profile without any significant impairment of glucose metabolism. GH replacement should therefore be considered in elderly GHD adults.

Interleukin-6 gene polymorphism -174G/C influences plasma lipid levels in women

Elevated levels of the pro-inflammatory cytokine interleukin-6 (IL-6) have been associated with cardiovascular risk factors. The objective of this study was to investigate potential associations between the promoter polymorphism IL-6 -174G/C and the following indices of metabolism: BMI, waist-to-hip ratio, and plasma levels of IL-6, cholesterol, low-density lipoprotein, triglycerides, high-density lipoprotein, leptin, and C-reactive protein in 252 42-year-old women and 245 51-year-old men. Subgroups were also studied 5 years later. The CC genotype of the IL-6 polymorphism was associated with lower levels of cholesterol and low-density lipoprotein (p < 0.001) in women. This finding was replicated in the follow-up, when a significant association between the CC genotype and low triglycerides was also observed. The association between the C allele and lipid pattern found in women was not found in men, where on the contrary, C carriers tended to display elevated triglycerides. IL-6 genotype was not associated with IL-6 plasma levels in either sample. The results suggest different effects of the IL-6 polymorphism on metabolic indices in women and men. None of the associations between IL-6 genotype and lipid pattern seemed to result from an effect of the polymorphism on IL-6 plasma levels.

Dyslipidemia and high waist-hip ratio in women with self-reported social anxiety

Previous research has indicated that phobic anxiety is associated with coronary heart disease. In this study, the possible association between social anxiety and various anthropometric, metabolic, and endocrine measurements known to be associated with cardiovascular disease were studied in a population-based cohort of 216 women 41-42 years old. Each participant was assessed by means of a DSM-IV based self-report questionnaire regarding social anxiety and related psychiatric diagnoses. Waist-to-hip ratio (WHR), body mass index (BMI), and serum levels of lipids and hormones were assessed. The prevalence of social anxiety was 14% (n=31). The social anxiety group displayed higher serum levels of triglycerides (1.3+/-0.9 vs. 1.0+/-0.5, P=0.003) and low-density lipoprotein (LDL) (3.3+/-0.8 vs. 3.0+/-0.7, P=0.03), but lower high-density lipoprotein (HDL) (1.4+/-0.3 vs. 1.6+/-0.4, P=0.04) and HDL/LDL ratio (0.46+/-0.15 vs. 0.57+/-0.22, P=0.008) than the other women. Serum levels of total testosterone (1.6+/-0.8 vs. 2.2+/-1.1, P=0.013) and free thyroxin (14+/-2 vs. 16+/-4, P=0.04) were lower in subjects confirming social anxiety. While WHR was significantly higher in the social anxiety group (0.83+/-0.06 vs. 0.80+/-0.07, P=0.016), BMI did not differ between the groups. Our data suggest that self-reported social anxiety is associated with two established risk factors for cardiovascular disease: dyslipidemia and increased WHR.

Baseline characteristics and the effects of two years of growth hormone replacement therapy in adults with growth hormone deficiency previously treated for Cushing's disease

OBJECTIVE

To determine baseline characteristics and the effects of 2 years of GH replacement therapy on body composition, muscle strength, bone mass, and metabolic indices in GH-deficient (GHD) adults previously treated for pituitary-dependent Cushing's disease.

DESIGN

A single-centre, open-labelled, prospective study.

PATIENTS

Fifteen consecutive GHD adults previously treated for pituitary-dependent Cushing's disease (CD group) and 15 closely matched GHD adults with previous nonfunctioning hypopituitary disease (NF group) were included. All patients had adult-onset GH deficiency.

RESULTS

The mean dose of GH was similar in both study groups during the 2-year treatment. At baseline, diastolic blood pressure was higher, and lumbar (L2-L4) bone mineral density (BMD) was lower, in the CD group than in the NF group. The increase in lean mass in response to GH therapy, as measured by dual-energy X-ray absorptiometry (DEXA), was less marked in the CD group. GH replacement therapy reduced diastolic blood pressure only in the CD group. The patients in the CD group had greater treatment response in lumbar (L2-L4) spine BMD and in isometric and isokinetic knee extension strength than the patients in the NF group. At study end, no difference remained between the two study groups.

CONCLUSIONS

This study revealed differences in the baseline characteristics between GHD patients previously treated for Cushing's disease as compared with closely matched GHD patients with previous nonfunctioning hypopituitary disease. The 2-year GH replacement therapy eliminated all the differences between the two study groups.

Growth hormone (GH) replacement in GH-deficient adults: a crossover trial comparing the effect on metabolic control, well-being and compliance of three injections per week versus daily injections

Growth hormone (GH) replacement therapy regimens in adults using daily subcutaneous (sc) injections may not be optimal with respect to carbohydrate and lipid metabolism. The aim of this study was to compare the efficacy of three times weekly injections with daily sc GH injections in terms of serum IGF-I, IGFBPs, lipoprotein levels, serum bone markers, glucose metabolism, body composition, compliance and well-being. Twenty hypopituitary men, 46-76 years, on a course of stable conventional GH replacement therapy for more than 12 months, were included in a 16-week crossover trial. During the first 8 weeks GH was administered three times per week followed by 8 weeks with daily sc injections with the same weekly dose of GH. Fasting serum samples were collected at baseline and on two consecutive days at the end of each 8-week period. Serum IGF-I and IGFBP-3 concentrations were lower both the first and second morning after the last injection during the period with three injections per week. The second morning after the last GH injection in this period the IGF-I/BP-3 ratio, plasma insulin and FFA were lower whereas IGFBP-1 was increased as compared with values obtained during the period with daily injections. Serum Lp(a) levels, body composition, fat distribution, well-being and compliance were not differently affected by the two treatment regimens. These results suggest that the same weekly dose of GH given as three injections per week reduces serum IGF-I and IGFBP-3 levels without affecting Lp(a) levels. The day-to-day variation in glucose metabolism and FFA serum levels differs considerably between the two modes of GH administration.

Serum lipids in fathers and sons at middle age: the study of sons to men born in 1913

OBJECTIVE

To relate lipid levels in middle-aged men to that of their fathers at 50 years of age measured 30 years earlier.

DESIGN AND SUBJECTS

In 1963, 855 men born in 1913 took part in a cardiovascular risk factor survey when they were at 50 years of age. In 1993, 475 sons to these men, aged 44-56, were invited to another examination; 263 of these men were examined (response rate: 56%) and compared with their 217 fathers when they were examined at 50 years of age in 1963. In the 1993 survey, 798 men aged 50, were also examined, from a general population sample of men born in 1943 (response rate: 55%).

SETTING

City of Göteborg, Sweden.

MAIN OUTCOME MEASURES

Serum lipids in sons as a function of lipids in their fathers.

RESULTS

Compared with the men born in 1913, both sons and men born in 1943 had lower mean serum cholesterol, but higher body mass index (BMI) and serum triglycerides. There was a significant relation between serum cholesterol in sons and their fathers (r = 0.25; P < 0.0001). Amongst sons to fathers in the highest cholesterol quartile (>6.9 mmol x L(-1)), 37% had serum cholesterol above 6.5 mmol x L(-1), compared with 16% amongst sons to fathers in the lowest quartile (<5.7 mmol x L(-1)) [adjusted odds ratio 3.73 (1.52-9.12)]. Sons to fathers with the highest serum cholesterol levels had slightly lower BMI; otherwise there was no relation between serum cholesterol in the father and any other lifestyle or biological risk factor in the sons. Serum triglyceride concentration in the father was unrelated to any variable in the son.

CONCLUSIONS

There was a moderately strong association between serum cholesterol concentration in fathers and sons at middle age. However, secular trends were also important in determining serum cholesterol concentrations in those born at a later period, indicating a major role of environmental factors.

The CYP19 gene and associations with androgens and abdominal obesity in premenopausal women

OBJECTIVE

Elevated androgens in women are associated with type 2 diabetes and are dependent on the conversion to estrogens by aromatase cytochrome P450. Polymorphisms of a tetranucleotide repeat [TTTA](n) in the fourth intron of the CYP19 gene are associated with endocrine-dependent diseases and were examined in relation to hormone levels and disease risk factors in premenopausal women.

RESEARCH METHODS AND PROCEDURES

A population sample of women born in 1956 (n = 270) were genotyped for this polymorphism and the results set in relation to steroid hormones, including saliva cortisol, anthropometric variables, estimates of insulin, glucose and lipid metabolism, and blood pressure.

RESULTS

Seven tetranucleotide repeat [TTTA](n) alleles were detected with allelic sizes of 168 to 195 bp, with a TCT deletion/insertion (168/171 bp) upstream of this microsatellite. Smoking was associated with elevated androgens (p = 0.005 to 0.019). Using the median (average stretch, 177.5 bp) as a dividing line, nonsmoking women with the shorter microsatellite had higher free testosterone (p = 0.018) and lower sex hormone binding globulin (p = 0.033). These differences were pronounced with the 168-bp allele. Such women were also characterized by a less-substantial decrease of morning cortisols ("unwinding"; p = 0.035) and central obesity (abdominal sagittal diameter, p = 0.049) and had waist/hip circumference ratios of borderline significance (p = 0.064).

DISCUSSION

The results indicate that, in premenopausal women, a short microsatellite in the fourth intron of the CYP19 gene, caused by a TCT deletion upstream the [TTTA](n) tract, is associated with elevated androgens, perturbed regulation of the hypothalamic-pituitary-adrenal axis, and abdominal obesity.

Intima-media thickness in cardiovascularly asymptomatic hypopituitary adults with growth hormone deficiency: relation to body mass index, gender, and other cardiovascular risk factors

OBJECTIVE

Increased cardiovascular mortality and carotid atherosclerosis have been observed in hypopituitary patients with untreated GH deficiency (GHD), but results are contradictory and relations to cardiovascular risk factors are not clear. The aim of this study was to investigate intima-media thickness (IMT) in relation to cardiovascular risk factors in adults with GHD.

DESIGN

Cross-sectional observational study of 21 men and 13 women with GHD, but without cardiovascular disease, compared to two healthy control groups matched for age, sex and smoking habits. One control group was matched for body mass index (BMI) and the other group was nonobese.

MEASUREMENTS

IMT of the carotid and femoral arteries, blood pressure, blood samples and anthropometric data.

RESULTS

Patients had 12% thicker composite carotid IMT [(IMT of common carotid artery + IMT of bulb)/2] compared to nonobese controls (P = 0.022), but IMT was not different compared to BMI-matched controls. Femoral IMT did not differ between patients and controls. Patients had higher waist : hip ratio (WHR), heart rate, serum triglycerides and fasting insulin concentrations in combination with lower high-density lipoprotein (HDL) cholesterol and smaller low-density lipoprotein (LDL) peak particle size compared to both nonobese and to BMI-matched controls. This cardiovascular risk pattern was more pronounced in female patients than in male patients compared to their gender controls. Carotid IMT was related to age, serum cholesterol, LDL cholesterol and smoking in the patient group. Only age was independently related to carotid IMT in multivariate analysis.

CONCLUSIONS

These results indicate that high BMI in GH-deficient patients contribute to their increased intima-media thickness. However, several cardiovascular risk factors are present in this patient group independent of their increased BMI, especially in women.

Effects of seven years of GH-replacement therapy on insulin sensitivity in GH-deficient adults

The few trials in GH-deficient (GHD) adults that have investigated the long-term effects of GH-replacement therapy on insulin sensitivity have shown conflicting results. In this study, insulin sensitivity was determined using the hyperinsulinemic, euglycemic clamp technique in 11 GHD adults at baseline and after 6 months, 1 yr, 2 yr, and 7 yr of GH-replacement therapy. Furthermore, insulin sensitivity in the GHD patients was compared with that in 11 matched control subjects at baseline and with that in 11 other matched controls at study end. The mean initial GH dose was 1.10 mg/d. The dose was gradually lowered; and after 7 yr, the mean dose was 0.61 mg/d. A sustained reduction in body fat and a sustained increase in fat-free mass were observed. Serum high-density lipoprotein-cholesterol (HDL-C) increased, and serum low-density lipoprotein-cholesterol (LDL-C) decreased, after 7 yr of treatment. Fasting blood glucose was transiently increased during the first year of GH replacement. The glucose infusion rate/body weight (GIR/BW), as measured using the hyperinsulinemic, euglycemic clamp technique, was unaltered during GH-replacement therapy. The comparisons with the control subjects revealed that GIR/BW in the GHD patients was 45% of that in the control subjects at baseline; whereas, at study end, the GIR/BW was 71% of that in the control subjects (P = 0.06 vs. baseline). This could suggest that GH-replacement therapy may prevent the age-related decline in insulin sensitivity in GHD patients.

The lean woman

OBJECTIVE

In the current obesity epidemic, the ability to remain lean is beginning to be uncommon. Therefore, it was considered of interest to characterize such subjects.

RESEARCH METHODS AND PROCEDURES

From a population of premenopausal women (n = 270), all 40 years of age, those with a similar body mass index (BMI) as women at the age of 21 years, born the same year (BMI = 21.1 kg/m(2)) were selected among nonsmokers and compared with the remaining nonsmoking women.

RESULTS

Lean women showed, as expected, low waist-to-hip circumference ratio and abdominal sagittal diameter as well as absence of other disease risk factors. Compared with the remaining women, 17 beta-estradiol was high and androgens were low, whereas insulin-like growth factor I and thyroid hormones showed no differences. Dihydroepiandrosterone sulfate was lower, whereas cortisol, measured in saliva repeatedly over a day, and adrenocorticotropin hormone were not different. Results from questionnaires indicated higher education and socioeconomic status, frequent sports activities, and better psychosocial adaptation and psychological health. A tetranucleotide repeat polymorphism in the fourth [corrected] intron of the aromatase P450 gene was longer among the lean (187 base pairs) than the rest of the women. Women with opposite phylogenetic characteristic have a short microsatellite (168 base pairs) in this gene locus.

DISCUSSION

Lean, nonsmoking women enjoy an excellent health in not only anthropometric and metabolic factors, but also in neuroendocrine, endocrine, and psychological variables. The endocrine measurements suggest a well-functioning aromatase, which in turn might have a genetic background, contributing to health. The aromatase gene might be important for regulation of body fat mass.

Treatment of abdominally obese men with a serotonin reuptake inhibitor: a pilot study

OBJECTIVE

To investigate the effects of a selective serotonin reuptake inhibitor (SSRI) on the neuroendocrine and autonomic nervous system perturbations found in abdominal obesity.

DESIGN

Treatment for 6 months with citalopram and for 6 months with placebo using a double-blind, cross-over design, with a 2-month wash-out period between treatment periods.

SUBJECTS

Sixteen healthy men, 45-60 years, moderately obese and with an abdominal fat distribution.

MEASUREMENTS

Anthropometry, three different depression rating scales, serum lipids, testosterone, IGF-I, oral glucose tolerance test (OGTT), pituitary stimulation with corticotropin releasing hormone (CRH), arithmetic stress test, and excretion of cortisol and metoxycatecholamines in urine, collected during 24 h.

RESULTS

Cortisol concentrations in the morning were low before treatment, indicating a perturbed function of the hypothalamic-pituitary-adrenal (HPA) axis. After treatment with citalopram morning cortisol concentrations rose to normal. Cortisol concentrations after stimulation with CRH or stress were elevated by citalopram treatment, but urinary cortisol excretion was unchanged. The glucose concentrations after OGTT (120 min) tended to be reduced, with unchanged insulin concentrations, whilst other metabolic values did not change during treatment. Heart rate after administration of CRH, and during laboratory stress test, decreased by treatment with citalopram. Diurnal urinary excretion of metoxycatecholamines tended to decrease. Neither body mass index nor waist/hip circumference ratio decreased. Depression scores were within normal limits before treatment and did not change.

CONCLUSION

The results of this pilot study indicate improvements in the regulation of neuroendocrine-autonomic systems as well as metabolism in abdominal obesity during treatment with an SSRI.

Polymorphism in exon 6 of the dopamine D(2) receptor gene (DRD2) is associated with elevated blood pressure and personality disorders in men

A deficient dopamine D(2) receptor (DA2) formation or action may contribute to hypertension via an increase of catecholamine release. In addition, Axis II personality disorders that appears odd or eccentric (cluster A) is associated with a low density of DA2. This study sought to examine if a NcoI restriction fragment length polymorphism (C to T transition) in exon 6 of the dopamine D(2) receptor gene (DRD2) was associated with these characteristics. The genotypes (CC, CT and TT) were compared in anthropometric, endocrine, metabolic and haemodynamic variables as well as estimates of personality disorders in 284 randomly selected 51-year-old men. Homozygotes for the C allele constituted 49% of the men and homozygotes for the T allele 9%, while heterozygotes were 41%. The TT genotype was associated with elevated systolic and diastolic blood pressure, independent of obesity and endocrine abnormalities, including the hypothalamic-pituitary-adrenal axis regulation. Moreover, the TT genotype was significantly more frequent among subjects with grade 1 (mild) hypertension (>140/90 mm Hg) compared to normotensive subjects (<130/85 mm Hg). The polymorphism in exon 6 of the DRD2 was also significantly associated with cluster A personality disorders. These results suggest that a polymorphism in exon 6 of the DRD2examined with the restriction enzyme NcoI is associated with an elevated blood pressure, independent of obesity. Paranoid or schizoid personality disorders is also associated with a polymorphism of the DRD2, which might be associated with a previously demonstrated low density of this receptor.

The activity of the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system in relation to waist/hip circumference ratio in men

OBJECTIVE

To investigate possible differences, between generally and abdominally obese men, in activity and regulation of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system.

RESEARCH METHODS AND PROCEDURES

Fifty non-diabetic, middle-aged men were selected to obtain two groups with similar body mass index (BMI) but different waist/hip circumference ratio (WHR). Measurements were performed of the activity of the HPA axis and the sympathetic nervous system, as well as metabolic and endocrine variables.

RESULTS

Men with a high WHR, in comparisons with men with a low WHR, had higher insulin, glucose, and triglyceride values in the basal state and higher glucose and insulin after an oral glucose tolerance test. Men with high WHR had elevated diurnal adrenocorticotropic hormone (ACTH) values but similar cortisol values, except lower cortisol values in the morning. Diurnal growth hormone concentrations showed reduced peak size. Stimulation of the HPA axis with corticotropin-releasing hormone (CRH) and laboratory stress showed no difference in ACTH values between groups, but cortisol values were lower in men with high WHR. In comparison with men with a low WHR, men with a high WHR had elevated pulse pressure and heart rate in the basal state and after challenges by CRH and laboratory stress. They also had increased urinary excretion of catecholamine metabolites.

DISCUSSION

These results suggest a mild dysregulation of the HPA axis, occurring with elevated WHR independent of the BMI. The results also indicate a central activation of the sympathetic nervous system, such as in the early phases of hypertension, correlating with insulin resistance.

A nine-month, placebo-controlled study of the effects of growth hormone treatment on lipoproteins and LDL size in abdominally obese men

Abdominal/visceral obesity is associated with blunted growth hormone (GH) secretion and an unfavourable lipoprotein pattern. In this study, the effect of GH treatment on LDL size and on serum lipoprotein concentrations was determined in abdominally obese men. Thirty men, aged 48-66 years, with a body mass index (BMI) of 25-35 kg/m(2)and a waist:hip ratio of >0.95, received treatment with GH (9. 5 microg/kg/day) or placebo for 9 months. Serum concentrations of total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C) and apolipoprotein B (apoB) were reduced (P<0.05, P<0.05 and P<0.001 vs placebo, respectively). Serum lipoprotein(a) [Lp(a)] concentration increased (P<0.05 vs. placebo). Mean low density lipoprotein (LDL) particle diameter was marginally increased by active treatment as compared with placebo (P =0.08). No changes were observed in the serum concentrations of high density lipoprotein-cholesterol (HDL-C), apolipoprotein A-I (apoA-I) and apolipoprotein E (apoE). In conclusion, 9 months of GH treatment in abdominally obese men beneficially reduced serum concentrations of TC, LDL-C and apoB, and marginally increased mean LDL diameter, while serum Lp(a) increased. The ultimate effect of GH therapy on the cardiovascular risk remains, however, to be determined.

A glucocorticoid receptor gene marker is associated with abdominal obesity, leptin, and dysregulation of the hypothalamic-pituitary-adrenal axis

OBJECTIVE

Abdominal obesity has a key role in the pathogenesis of prevalent and serious diseases and has been shown to be associated with an altered hypothalamic-pituitary-adrenal (HPA) axis function, which is regulated by endocrine feedback mediated via hippocampal glucocorticoid receptors (GR).

RESEARCH METHODS AND PROCEDURES

We examined the HPA axis function by repeated salivary samples for the assessment of cortisol, as well as other endocrine, anthropometric, metabolic, and circulatory variables in middle-aged Swedish men (n = 284). With the restriction enzyme BclI, variants of the GR gene (GRL) locus were identified and two alleles with fragment lengths of 4.5 and 2.3 kilobases (kb) were detected.

RESULTS

The observed frequencies were 40.1% for the 2.3- and 2.3-kb, 46.2% for the 4.5- and 2.3-kb, and 13.7% for the 4.5- and 4.5-kb genotypes. The larger allele (4.5 and 4.5 kb) was associated with elevated body mass index (BMI; p < 0.001), waist-to-hip circumference ratio (p = 0.015), abdominal sagittal diameter (p = 0.002), leptin (p < 0.001), and systolic blood pressure (borderline, p = 0.058). The 4.5- and 4.5-kb allele was associated with leptin after adjustment for BMI. Moreover, salivary cortisol values, particularly after stimulation by a standardized lunch (p = 0.040 to 0.086), were elevated in the men with the larger allele.

DISCUSSION

These results indicate that there is an association between a deficient GR function, defined as a poor feedback regulation of the HPA axis activity, and a polymorphic restriction site at the GR gene locus. An abnormal control of HPA axis function due to genetic alterations may contribute to the pathogenesis of abdominal obesity.

Secular changes in cardiovascular risk factors over 30 years in Swedish men aged 50: the study of men born in 1913, 1923, 1933 and 1943

OBJECTIVES

To study secular trends in cardiovascular risk factors in men aged 50 over a period of 30 years.

DESIGN

Cross-sectional studies of successive cohorts of men from 1963 to 1993.

SETTING

City of Göteborg, Sweden.

SUBJECTS

Four random population samples of men born in 1913, 1923, 1933 and 1943, aged 50 when they were examined in 1963, 1973, 1983, and 1993 (n = 855, 226, 776, and 798, respectively).

MAIN OUTCOME MEASURES

Anthropometric measurements, blood pressure, serum cholesterol and triglycerides and smoking habits over three decades.

RESULTS

Over 30 years, men increased in weight from a mean (SD) of 75.9 (11.0) kg to 82.8 (12.1) kg and gained 3.4 cm in height, with a net increase in body mass index from 24.8 (3.2) to 26.0 (3.4) kg m-2 (P < 0.0001), and a concomitant increase in waist circumference. The proportion of men who were overweight but not obese (BMI = 25-30 kg m-2) increased from 38 to 47%, whereas the prevalence of frank obesity (more than 30 kg m-2) increased from 6% in 1963 to 11% in 1993. Despite the increase in weight, mean systolic blood pressure fell by almost 10 mmHg (P < 0.0001). Mean serum cholesterol concentration decreased from 6.42 (1.12) to 5.88 (1.04) (P < 0.0001). Serum triglycerides increased from 1.26 (0.77) to 1.69 (1.04) mmol L-1 (P = 0.001). The proportion of men who smoked decreased from 56% in 1963 to 30% in 1993 (P < 0.0001). This was due more to an increase in smoking cessation rates than to an increase in the proportion of men who had never smoked. In particular, smokers and former smokers are now more obese than the corresponding categories 30 years ago and smokers are no longer leaner than men who have never smoked.

CONCLUSIONS

Over a period of 30 years, serum cholesterol as well as systolic blood pressure and the prevalence of smoking decreased. This favourable decline in coronary risk factors was offset by an appreciable increase in body mass index and waist circumference.

Treatment of obese subjects with the oral growth hormone secretagogue MK-677 affects serum concentrations of several lipoproteins, but not lipoprotein(a)

Obesity is associated with blunted GH secretion and an unfavorable lipoprotein pattern. The objective of this study was to investigate the effects of treatment with the oral GH secretagogue MK-677 on lipoproteins in otherwise healthy obese males. The study was randomized, double blind, and parallel. Twenty-four obese males, aged 18-50 yr, with body mass index greater than 30 kg/m2 and waist/hip ratio above 0.95 were treated with 25 mg MK-677 (n = 12) or placebo (n = 12) daily for 8 weeks. MK-677 treatment did not significantly change serum lipoprotein(a) [Lp(a)] levels. Serum apolipoprotein A-I and E (apoA-I and apoE) were increased at 2 weeks (P < 0.001 and P < 0.01 vs. placebo, respectively), but were not changed at study end. Serum total cholesterol and low density lipoprotein (LDL) cholesterol (LDL-C) levels were not significantly changed by MK-677 treatment. Serum high density lipoprotein (HDL) cholesterol (HDL-C) was increased at 2 weeks of MK-677 treatment (P < 0.01 vs. placebo), but not at 8 weeks. The LDL-C/HDL-C ratio was reduced after 8 weeks of MK-677 treatment (P < 0.05 vs. placebo). Mean LDL particle diameter was decreased at 2 weeks (P < 0.05 vs. placebo), but was unchanged compared with baseline values at 8 weeks (P = NS vs. placebo). The level of serum triglycerides was increased at 2 (P < 0.05 vs. placebo), but not at 8, weeks. Lipoprotein lipase activity in abdominal and gluteal sc adipose tissue was not affected by active treatment. In conclusion, treatment with the oral GH secretagogue MK-677 affected circulating lipoproteins. The effects on serum apoA-1, apoE, triglycerides, and mean LDL particle diameter were transient. At study end, the LDL-C/HDL-C ratio was decreased. MK-677 treatment did not significantly affect serum Lp(a) concentrations at the present dose and administration protocol.

Endocrine and metabolic aberrations in men with abdominal obesity in relation to anxio-depressive infirmity

Abdominal obesity, anxiety, and depression have been found to cluster in several studies. To further characterize these associations, the following study was performed. In a population of 51-year-old men (N = 284), measurements of obesity (body mass index [BMI]) and body fat distribution (waist to hip ratio [WHR] and sagittal trunk recumbent diameter [D]) were analyzed in relation to dexamethasone (0.5 mg) inhibition of cortisol secretion, measured as salivary cortisol. Symptoms of anxiety and depression were defined by a validated questionnaire. Furthermore, testosterone, insulin-like growth factor-I (IGF-I), insulin, glucose, and serum lipid levels were measured. Twenty-five men (8.8%) had symptoms of anxiety and depression. BMI, WHR, and D correlated negatively with testosterone, except for BMI in the anxio-depressive (ADP) group. IGF-I showed no significant relationship. Furthermore, fasting insulin and the insulin to glucose ratio correlated positively and high-density lipoprotein (HDL) cholesterol correlated negatively with BMI, WHR, and D in the total study population and in the subgroups. Total and low-density lipoprotein (LDL) cholesterol showed no significant relationships. Correlation coefficients tended to be higher in ADP men. Dexamethasone inhibition showed a negative significant relationship with BMI (rho = -.47, P = .025), WHR (borderline, rho = -.37, P = .086), and D (rho = -.43, P = .046) only in the ADP group. Comparing the ADP group versus the group without anxio-depression (ADO) and high or low BMI (P = .008), WHR (P = .026), and D (P = .012) showed blunted dexamethasone inhibition only in ADP men with high anthropometric measurements. These findings suggest there is a subgroup with elevated BMI, WHR, and D in whom a blunted dexamethasone response is found associated with traits of anxiety and depression, conditions characterized by such an abnormality. The reason for the association might be insufficient control of cortisol secretion, followed by visceral fat accumulation.

Comparison of antioxidant activity in lipoprotein fractions from insulin-dependent diabetics and healthy controls

The insulin-dependent diabetic patient is at greatly increased risk of premature atherosclerosis. Oxidative damage to lipoproteins has been implicated as an important factor in the atherogenic process. Diabetic patients are exposed to excessive oxidative stress because of non-enzymatic glycation of proteins and a variety of defects in antioxidant systems. We have previously described an enhanced chemiluminescent method for measuring protective 'chain-breaking' antioxidant activity in plasma lipoprotein fractions. In this study we compare the lipid content and antioxidant activity of plasma lipoproteins in 22 young insulin-dependent diabetics without vascular complications and 20 age- and sex-matched controls. Mean levels of haemoglobin A 1c in the diabetic group were 8.8 +/- 0.2%. There were no significant differences in serum total cholesterol, apolipoprotein A, apolipoprotein B or lipoprotein(a) levels between the study groups. Serum total triglyceride levels (1.32 +/- 0.11 versus 1.01 +/- 0.08 mmol/l; P < 0.05) and LDL-associated triglyceride (0.28 +/- 0.04 versus 0.15 +/- 0.02 mmol/l; P < 0.05) were significantly elevated in the diabetic group. Total plasma antioxidant activity was significantly reduced in the diabetic group (272.0 +/- 15.4 versus 338.3 +/- 20.7 micromol/l; P < 0.05). Antioxidant activity measured in five lipoprotein fractions isolated by density gradient ultracentrifugation (VLDL1. VLDL2, LDL1, LDL2 and HDL) showed no significant differences between groups when corrected for protein, total lipid or cholesterol content. When corrected for triglyceride content significantly lower antioxidant values were found in the diabetic HDL fraction only. The results of this study imply that the susceptibility of the insulin-dependent diabetic to the development of premature atherosclerosis cannot be attributed to reduced antioxidant activity in circulating plasma lipoproteins.

On quantifying plaque size and intima-media thickness in carotid and femoral arteries. Comments on results from a prospective ultrasound study in patients with familial hypercholesterolemia

The aim of the present analysis in an ongoing observational study was to evaluate the possibility of measuring plaque size in ultrasound images from carotid and femoral arteries and the usefulness of quantitative plaque measurements in such a prospective study. Twenty-five patients with carotid plaques were identified in a group of patients with familial hypercholesterolemia (n = 50) compared with 7 subjects in a low-risk control group (n = 47). Only 20 of the 32 recorded plaques were accessible for quantitative follow-up measurements of area, base length, and thickness, which represents only 21% of all subjects investigated. In contrast, paired observations of intima-media thickness in the common carotid artery were available in 98% and in the carotid bulb in 87% of the subjects investigated. In those with paired observations of plaque area available, the data indicated a close relationship between the 2-year change recorded in plaque area and the 2-year change in intima-media thickness measured in a 10-mm-long predefined section of the carotid bulb (r = .81, P < .001, n = 19). The corresponding relationship between change in plaque area and change in a 10-mm-long section of the common carotid artery was r = .38 and P < .05 (n = 20). Quantitative measurements of plaques in the femoral arteries were also performed, but the results from these measurements were in most cases judged not to be useful. However, measurements of intima-media thickness in a 15-mm-long predefined section of the common femoral artery may be performed in a reproducible way in most patients. We conclude that the usefulness of plaque area measurements in prospective studies of the carotid artery seems limited because plaques available for quantitative measurements are present in only a small proportion of subjects. However, reproducible measurements of intima-media thickness in a predefined section of the carotid bulb are achievable in most subjects, and our data indicate that the changes recorded over time in the carotid bulb closely mirror changes occurring in the size of atherosclerotic plaques within the carotid artery region. In addition, present data indicate that measurements of intima-media thickness in the common carotid artery complement measurements performed in the carotid artery bulb in the study of early atherosclerosis.

Inhibition of cortisol secretion by dexamethasone in relation to body fat distribution: a dose-response study

There is now evidence of a hypersensitive hypothalamo-pituitary-adrenal (HPA) axis in subjects with an elevated waist/hip circumference ratio (WHR), an indicator of the centralization of body fat stores. The activity of the HPA axis is regulated by central glucocorticoid receptors, whose activity can be tested by the administration of exogenous glucocorticoids, which normally inhibit cortisol secretion. In this study, dexamethasone (dex) was administered in random order in doses of 0.05, 0.125, 0.25 and 0.5 mg at 10 p.m. with measurements of serum cortisol in the morning (8 a.m.) of this and the following day. The test was performed on 22 apparently healthy men, 40 to 60 years of age, recruited from laboratory personnel, outpatient clinics or advertisements in a newspaper. Eight had a body mass index (BMI) (kg/m2) of < 25 and 14 of > 25. Twelve men had a waist hip ratio (WHR) of < 1.0 and 10 men had a WHR of > 1.0. Cortisol values at baseline were correlated inversely with WHR and were usually lower in men with a high (> 1.0) rather than a low than low (< 1.0) WHR after dex inhibition. There was apparently no inhibition by dex at 0.05 and 0.125 mg on average in men with a WHR of > 1.0. In addition, the inhibition at 0.5 mg dex correlated negatively with the WHR and was significantly lower (p < 0.05) in men with a WHR of > 1.0 than in men with a WHR of < 1.0. None of these differences or relationships was found to be dependent on BMI. It is concluded that men with an elevated WHR experience a decrease in the inhibition of cortisol secretion by dex. It is suggested that this could explain or contribute to the elevated sensitivity of their HPA axis. Furthermore, lower morning cortisol concentrations suggest a change in diurnal secretion patterns.

Multiple risk intervention in high-risk hypertensive patients. A 3-year ultrasound study of intima-media thickness and plaques in the carotid artery. Risk Intervention Study (RIS) Group

In spite of optimal blood pressure control, available data indicate that the risk of coronary heart disease remains high in many patients with hypertension. Multifactorial risk intervention programs have therefore been advocated. The aim of the present randomized study was to analyze whether a favorable change in risk factors caused by a comprehensive risk factor modification program (focused mainly on nonpharmacological intervention) might beneficially affect ultrasound-assessed far-wall common carotid intima-media thickness or plaques in the carotid artery in high-risk hypertensive patients (n=81) in comparison with those undergoing usual care (n=83). A further aim was to analyze whether risk factors measured at baseline or follow-up were related to the change recorded in intima-media thickness during follow-up. The results showed in the intervention group a favorable change in LDL cholesterol (-9%), in smoking habits (32% of smokers quit smoking), and in HbA1c (-17% in patients with diabetes mellitus) over the 3.5-year observation period. However, no difference between the two randomization groups could be observed for far-wall common carotid intima-media thickness or plaque status during follow-up. Of all tested potential risk factors, only fasting insulin at baseline (available in nondiabetic patients) was significantly related to the change in mean intima-media thickness during follow-up (r=.25, n=92, P<.01). The relationship (negative) between follow-up serum HDL and change in mean intima-media thickness during the preceding follow-up was of borderline significance. Patients with moderate to large plaques in the carotid artery region at baseline had a significantly larger increase in common carotid artery intima-media thickness during follow-up than patients with no or only small plaques. The results are disappointing and may indicate that either the change in risk factors occurred too late in life or a considerably larger change in concomitant risk factors than we observed is needed to favorably affect intima-media thickness during an observation period of around 3 years in high-risk hypertensive patients.

Two weeks of daily injections and continuous infusion of recombinant human growth hormone (GH) in GH-deficient adults. II. Effects on serum lipoproteins and lipoprotein and hepatic lipase activity

Recombinant human growth hormone (GH) administered as daily subcutaneous (SC) injections has been shown to affect serum lipoproteins in GH-deficient subjects. However, the effects of continuous infusion of GH on serum lipoproteins have not been investigated in GH-deficient adults. The aim of the present study was to compare effects of daily injections and continuous infusion of GH on lipoprotein metabolism. Recombinant human GH (0.25 U/kg/wk) was administered to nine GH-deficient adult men during a period of 14 days in two different ways, ie, as a daily SC injection at 8:00 PM and as a continuous SC infusion, with 1 month of washout between the treatments. Blood samples and tests were performed in the morning after an overnight fast before the start of GH treatment (day 0) and on day 2 and day 14 of treatment. Abdominal SC adipose tissue lipoprotein lipase (LPL), postheparin plasma LPL, and hepatic lipase (HL) activity were measured 120 minutes after the intake of 100 g glucose. Adipose tissue LPL activity decreased and postheparin plasma HL activity increased after 14 days of GH treatment irrespective of the mode of GH administration, whereas GH treatment had no effect on postheparin plasma LPL activity. Serum triglyceride and very-low-density lipoprotein (VLDL) triglyceride concentrations increased during GH treatment. However, VLDL triglyceride concentrations increased to a greater degree during treatment with daily GH injections than during continuous infusion of GH. Serum apolipoprotein (apo) B and low-density lipoprotein (LDL) cholesterol concentrations decreased during treatment with daily GH injections, but were not significantly affected by continuous GH infusion. Thus, apo B and LDL cholesterol concentrations were lower after daily GH injections versus continuous GH infusion. Serum lipoprotein(a) [Lp(a)] and apo E concentrations increased during both modes of GH treatment. However, continuous infusion of GH resulted in a more marked increase in Lp(a) and apo E concentrations than daily GH injections. Minor effects were observed on serum apo A-I concentrations but high-density lipoprotein (HDL) cholesterol concentrations were not affected. In conclusion, GH treatment of GH-deficient men influenced adipose tissue LPL and postheparin plasma HL activity, as well as serum lipoprotein concentrations. Moreover, continuous GH infusion and daily GH injections differed with respect to the magnitude of effects on several lipoprotein fractions including VLDL triglycerides, LDL cholesterol, apo B, apo E, and Lp(a) concentrations.

Insoluble complex formation between LDL and arterial proteoglycans in relation to serum lipid levels and effects of lipid lowering drugs

Lipoprotein deposition and increased intimal proteoglycans are characteristics of the atherosclerotic lesion in which low density lipoproteins (LDL) bind with high affinity to proteoglycans. The affinity of LDL to proteoglycans is dependent on its structural and compositional characteristics. This study investigated the relationship between serum lipid levels and LDL-proteoglycan reactivity. We also analyzed how lipid-lowering drugs affect this interaction. Patients with moderate hypercholesterolemia (n = 147) were randomized to pravastatin 40 mg o.d., gemfibrozil 600 mg b.i.d., gemfibrozil+pravastatin (same doses) or placebo. LDL reactivity with proteoglycans was analyzed by precipitation of serum with isolated human arterial proteoglycans. Reactivity was determined as amount of precipitated cholesterol or apolipoprotein (apo) B. Under the conditions used, 53% of the LDL cholesterol and 29% of serum apo B were precipitated. There were strong correlations between precipitated LDL and serum levels of cholesterol, LDL or apo B. No correlations were found with serum lipoprotein(a) (Lp(a)) levels. During pravastatin treatment, cholesterol was reduced by 26.5% and triglycerides by 9.8%. During gemfibrozil treatment corresponding figures were 16.8 and 40.2, and for the combined treatment, 27.5% and 34.2%. On all treatments, the reactivity of LDL with proteoglycan was reduced. The effects were significantly larger in the groups treated with gemfibrozil. This was correlated with the increase in high density lipoprotein (HDL) during gemfibrozil treatment. In hypercholesterolemia, the reactivity of LDL with proteoglycan is increased; treatment with lipid-lowering drugs lowers this reactivity, the effect being greatest for gemfibrozil. This might be due to conformational changes of LDL during treatment with gemfibrozil, unrelated to its lipid lowering effect. Since binding of LDL to proteoglycans is central in atherogenesis, this may be of importance for the role of gemfibrozil as an antiatherogenic drug.

N-acetylcysteine treatment lowers plasma homocysteine but not serum lipoprotein(a) levels

High levels of lipoprotein(a) (Lp(a)) or homocysteine in plasma have both been associated with an increased risk for premature cardiovascular disease. For both components, the plasma levels are primarily genetically determined, and they have been very restintant to therapeutic approaches. It has been suggested that N-acetylcysteine (NAC) breaks disulphide bonds in Lp(a) as well as between homocysteine and plasma proteins. In the present study we analyze if this mechanism, in vivo, could be used to lower plasma concentrations of Lp(a) and homocysteine. Treatment with NAC and placebo was performed in a double blind cross over design with 2 weeks wash-out between treatments. Eleven subjects with high plasma Lp(a) (> 0.3 milligram) were recruited from the Lipid Clinic at Sahlgren's Hospital, Göteborg, Sweden. Main outcome measures were treatment effects on plasma Lp(a) and plasma amino thiols (homocysteine, cysteine and cysteinyl glycine). There was no significant effect on plasma Lp(a) levels. Plasma thiols were significantly reduced during treatment with NAC: homocysteine by 45% (P < 0.0001), cysteinyl glycine by 24% (P < 0.0001) and cysteine by 11% (P = 0.0002). The high dose of NAC was well tolerated. In conclusion NAC has no effect on plasma Lp(a) levels while the reduction in homocysteine is considerable and might be of clinical significance in cases with high plasma homocysteine levels.

Effects of 1 year of growth hormone therapy on serum lipoprotein levels in growth hormone-deficient adults. Influence of gender and Apo(a) and ApoE phenotypes

We investigated the influence of gender and apoE and apo(a) phenotypes as well as the effect of the metabolic effects of growth hormone (GH) on the effect of GH therapy on serum lipoprotein concentrations in GH-deficient (GHD) adults. Forty-four consecutive patients, 30 men and 14 women aged 46.5 (range, 19 to 76) years with GHD due mainly to pituitary tumors, were treated with recombinant human GH for 12 months. Serum concentrations of lipoproteins, insulin, thyroxine, and insulin-like growth factor-I were determined, body composition was assessed by bioelectrical impedance, and apo(a) and apoE phenotypes were analyzed. Lipoprotein(a) [Lp(a)] concentrations in the GHD subjects were compared with a gender- and apo(a) phenotype-matched control group. After 12 months of GH treatment, the total cholesterol, LDL cholesterol, and apoB concentrations decreased, the HDL cholesterol and apoE concentrations increased, and the apoA-I and triglyceride concentrations were unchanged. Before treatment, the Lp(a) concentration was similar to that in the control group. However, after 12 months of treatment, the Lp(a) concentration had increased by 44% and 101% above baseline and the control group, respectively. Men and women responded differently to GH, with a more marked increase in Lp(a) concentration and fat-free mass and a more pronounced decrease in body-fat mass in men. Apo(a) phenotypes had no major influence on the effect of GH therapy. The only significant difference between apoE phenotypes was a higher baseline Lp(a) concentration among apoE4 heterozygotes.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute supplementation with the nitric oxide precursor L-arginine does not improve cardiovascular performance in patients with hypercholesterolemia

Endothelial dysfunction based on lack of nitric oxide (NO) may contribute to several settings of cardiovascular disorder. Chronic oral supplementation with the NO precursor L-arginine counteracts the development of aortic atherosclerosis in cholesterol-fed rabbits, and i.v. infusion of L-arginine may acutely improve endothelium-dependent coronary epicardial vasodilation in patients with hypercholesterolemia (HC). To clarify whether excess NO precursor may also improve general cardiovascular performance in HC, we measured working capacity indices of myocardial ischemia, and basal and post-occlusive forearm and skin blood flow in nine patients with elevated plasma cholesterol (9.1 +/- 0.2 mumol/l) following random double-blinded administration of L-arginine (16 g i.v.) or placebo. Infusion of L-arginine raised the plasma concentration of this amino acid from 85 +/- 12 to 2460 +/- 230 mumol/l but did not change the plasma level of the major NO metabolite nitrate. Maximal working capacity, indices of myocardial ischemia, and basal and post-occlusive blood flow in the skin or forearm did not differ between the treatments. The lack of positive effect of L-arginine compared to placebo indicates that excess NO precursor did not improve microvascular endothelial function in the patients, or alternatively, that the indices measured in the present study were not dependent on endothelial microvessel function. Thus, in patients with HC, deficiency of precursor for NO formation does not seem to impair either maximal exercise capacity myocardial perfusion during maximal exercise, or maximal vasodilator capacity in skeletal muscle or skin.

Intima-media thickness after cholesterol lowering in familial hypercholesterolemia. A three-year ultrasound study of common carotid and femoral arteries

Patients with familial hypercholesterolemia (FH) (n = 53) were examined with B-mode ultrasound before and after 3 years of cholesterol-lowering therapy with pravastatin, cholestyramine, or a combination. The aim was to measure the progression rate of intima-media thickening during follow-up in the common carotid and common femoral arteries. Since for ethical reasons it was not possible to perform a randomized placebo controlled study in patients with FH, we chose to recruit an untreated control group with lower risk, matched for sex, age, height and weight, and with serum cholesterol below 6.5 mmol/l. At baseline, intima-media thickness was larger in the hypercholesterolemic group than in the control group in both the common carotid and common femoral arteries. The difference between the change over 3 years observed in the control group and the change observed in the hypercholesterolemic group was calculated and defined as 'net difference'. There was a -32% net difference in low density lipoprotein (LDL) in the hypercholesterolemic group during follow-up. The ultrasound investigation showed a concomitant net difference of -0.06 mm in mean carotid intima-media thickness (95% confidence interval, -0.11 to -0.01 mm) and of -0.09 mm in maximum carotid intima-media thickness (P < 0.05, 95% confidence interval, -0.16 to -0.01 mm), with no net change in lumen diameter. No decrease was recorded in common femoral intima-medial thickness. Seventeen of the patients with FH had a positive history of myocardial infarction (MI) and this subgroup had a significantly larger decrease in mean carotid intima-media thickness during follow-up than the subgroup of patients with a negative history of MI (P < 0.01). In conclusion, the results showed a reduction in common carotid intima-media thickness after long-term cholesterol-lowering therapy in patients with FH. This finding may indicate a beneficial effect on atherosclerosis development in these patients.

Ultrasound evaluation of atherosclerotic manifestations in the carotid artery in high-risk hypertensive patients. Risk Intervention Study (RIS) Group

The aim of this study was to evaluate whether high-risk hypertensive patients (n = 137) had larger far-wall common carotid artery intima-media thickness than a control group (n = 37) and to study whether intima-media thickness was related to other signs of atherosclerotic disease. The results showed that intima-media thickness was significantly larger in the hypertension group than in the control group. Lumen diameter and mean cross-sectional area of the intima-media complex were larger both for hypertensive patients with a positive history of manifest clinical cardiovascular disease and for hypertensive patients with no such history than in the control group. There was a significant relationship between far-wall common carotid artery intima-media thickness and plaque status (visual scoring, no, small, moderate/large) in the carotid artery region. In univariate analyses, low diastolic blood pressure and high pulse pressure were both significantly related to plaque status. In multivariate analyses, pulse pressure was significantly and independently related both to common carotid artery intima-media thickness and to plaque status in the carotid artery region. In multivariate analyses, there was also an independent relationship between age and common carotid artery intima-media thickness, between smoking status and plaque status, and between a positive history of manifest clinical cardiovascular disease and plaque status. In conclusion, common carotid artery intima-media thickness and lumen diameter were increased in elderly high-risk hypertensive patients, in whom more than one third of the patients also had a moderate to large plaque in the carotid artery region.(ABSTRACT TRUNCATED AT 250 WORDS)

Low dose continuously infused growth hormone results in increased lipoprotein(a) and decreased low density lipoprotein cholesterol concentrations in middle-aged men

OBJECTIVE

Animal studies have shown that slight increases in basal GH concentrations may result in changes in lipoprotein metabolism. Such changes in GH secretion have been observed in physiological and pathophysiological states such as fasting, uncontrolled diabetes and during oestrogen treatment. The aim of this study was to investigate the possible effects of increases in basal plasma GH concentrations on lipoprotein concentrations.

DESIGNS

Recombinant human growth hormone (rhGH) was given as a continuous subcutaneous infusion in a low dose (0.02 U/kg/day) in an open study.

PATIENTS

Eight middle-aged (42-59 years) overweight (body mass index: 26.1-33.8 kg/m2) but otherwise healthy men were studied over a period of 14 days.

MEASUREMENTS

Blood samples were obtained after an over-night fast before and after 2, 7 and 14 days of treatment. Plasma and serum were separated and used for subsequent measurements of hormone and lipoprotein concentrations. On days 0, 7 and 14 of treatment, post-heparin plasma was also obtained for determinations of plasma lipoprotein lipase and hepatic lipase activities. In addition, a hyperinsulinaemic euglycaemic glucose clamp was performed on days 0 and 13 of the study. Fat biopsies from abdominal and gluteal fat depots were obtained for measurement of lipoprotein lipase activities on days 0 and 14 of the study.

RESULTS

Serum GH concentrations increased to a steady level of 2-4 mU/l during treatment. Serum insulin-like growth factor-I (IGF-I) concentrations increased throughout the treatment period to twice the pretreatment levels. Plasma insulin and blood glucose concentrations increased on day 2 of treatment. After 7 and 14 days of treatment blood glucose concentrations were not different from pretreatment levels, but plasma insulin concentrations were still elevated. Serum cholesterol and low density lipoprotein (LDL) cholesterol concentrations had decreased after 7 and 14 days of treatment. High density lipoprotein (HDL) cholesterol concentrations were not affected, but very low density lipoprotein (VLDL) cholesterol and triglyceride concentrations increased transiently at day 2 of treatment. Serum apolipoprotein (apo) A-I, apoB and apoE concentrations were not significantly affected. Serum lipoprotein(a) concentrations had increased by days 7 and 14 to 147 and 142% of pretreatment concentrations, respectively. Lipoprotein lipase and hepatic lipase activities in post-heparin plasma, as well as abdominal and gluteal adipose tissue lipoprotein lipase activities, were not affected. There was no significant change in glucose disposal rate estimated from the glucose clamp studies.

CONCLUSIONS

A low dose infusion of GH results in marked changes in lipoprotein concentrations with a transient increase in VLDL cholesterol and thereafter in a decrease in LDL cholesterol. In addition, this low dose of GH resulted in marked increases in lipoprotein(a) concentrations. The observed effects of GH may partly involve changes in IGF-I and insulin secretion.

Atherosclerotic changes in the femoral and carotid arteries in familial hypercholesterolemia. Ultrasonographic assessment of intima-media thickness and plaque occurrence

B-mode ultrasound is increasingly used in clinical research to study the atherosclerotic process in the carotid arteries. The present investigation evaluated the feasibility of measuring intima-media thickness in the common femoral artery and assessed whether such measurement might provide further information on the extent of the atherosclerotic process in patients with familial hypercholesterolemia. A further aim was to study the relationship between the intima-media thickness of the common carotid artery and the occurrence of plaque in the carotid and femoral arteries. The results showed an increased intima-media thickness in the far wall of the common femoral artery in patients with familial hypercholesterolemia compared with the control subjects (P < .01). The results also showed a clear relationship between the thickness of the intima-media complex in the common carotid artery and the prevalence of plaque in the carotid and femoral arteries. This may be interpreted as an indication that an increase in intima-media thickness in the common carotid artery at least partly expresses a generalized atherosclerotic process. The atherosclerotic changes appeared to be more advanced in the femoral artery compared with the carotid artery. In future studies, therefore, valuable information on different stages of atherosclerotic changes may be achieved by combining information from B-mode recordings from both the carotid and femoral arteries.

Growth hormone treatment of growth hormone-deficient adults results in a marked increase in Lp(a) and HDL cholesterol concentrations

The effects of growth hormone treatment of adults with adult-onset pituitary insufficiency on lipoproteins and apolipoproteins were investigated. Nine patients, one women and eight men (age range, 34-58 years), who had been treated for pituitary tumors were studied. They had complete pituitary insufficiency with a duration of at least 1 year. All patients received replacement therapy with thyroid hormones, glucocorticoids, and gonadal steroids. The study had a double-blind, placebo-controlled, crossover design for active treatment with recombinant human growth hormone (0.25-0.5 units/kg per week s.c. given each evening) for 6 months. Fasting serum levels of cholesterol; triglycerides; high density lipoprotein and low density lipoprotein cholesterol; apolipoproteins A-I, B, and E; and lipoprotein (a) were measured before and after 6 and 26 weeks of treatment. Lipoprotein (a) concentrations increased markedly during treatment and were about twice as high compared with pretreatment levels. Serum cholesterol and low density lipoprotein cholesterol concentrations were decreased after 6 weeks of treatment, but levels had returned to pretreatment levels after 26 weeks. High density lipoprotein cholesterol concentrations increased during treatment and were significantly higher than pretreatment levels after 26 weeks of treatment. Serum triglyceride concentrations did not change significantly, but in two patients with marked hypertriglyceridemia, growth hormone treatment resulted in a marked decrease. Serum concentrations of apolipoproteins A-I, B, and E did not change significantly, but changes in apolipoprotein A-I and B concentrations were in parallel to those observed for high density lipoprotein cholesterol and low density lipoprotein cholesterol, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased waist/hip ratio, metabolic disturbances, and family history of hypertension

To test whether nonhypertensive subjects with a two-generation positive family history of hypertension (PFH) are characterized by disturbed glucose metabolism, 16 men (38 +/- 6 years old) with PFH and 25 subjects matched for age and with negative family histories of hypertension (NFH) were recruited. Blood pressure; serum lipids; erythrocyte transmembrane sodium transport; and the glucose, plasma insulin, and C-peptide responses to an oral glucose tolerance test were investigated. Subjects with PFH had higher blood pressure, body weight, body mass index (BMI), waist/hip ratio (WHR), and abdominal sagittal diameter than subjects with NFH. Baseline blood glucose, plasma insulin, serum lipids, and transmembrane sodium transport did not differ between the two groups. Blood glucose levels at 90 and 120 minutes after oral glucose were significantly higher in subjects with PFH than in controls. Blood glucose adjusted for BMI and WHR at 90 minutes was significantly related to a PFH. Plasma insulin level at 90 minutes during the glucose load was significantly higher in subjects with PFH. In multivariate analysis, WHR was significantly related to baseline blood pressure, insulin, and cholesterol, whereas BMI was significantly associated with the insulin response to the oral glucose tolerance test. Transmembrane sodium transport was significantly related to blood pressure only. In conclusion, subjects with PFH are characterized by increased body weight and BMI, increased visceral fat accumulation, and an altered blood glucose response to an oral glucose load. It was also shown that WHR was related to blood pressure and that BMI was more related to cholesterol and response to glucose loading than a PFH was.

Arterial wall thickness in familial hypercholesterolemia. Ultrasound measurement of intima-media thickness in the common carotid artery

B-mode ultrasound was used to noninvasively determine wall thickness and lumen diameter in the common carotid artery in patients with familial hypercholesterolemia (n = 53) and in a control group (n = 53). The controls were matched for sex, age, height, and weight, and all had a serum cholesterol level below 6.5 mmol/l. The study was performed to evaluate whether the patients had a thicker arterial wall compared with that of the control group. Wall thickness was determined as the combined intima-media thickness of the far wall and is presented as the mean and maximum thickness of a 10-mm-long section of the common carotid artery. The difference between the groups was 0.13 mm in mean wall thickness (p less than 0.001; 95% confidence interval, 0.07-0.18 mm) and 0.20 mm in maximum wall thickness (p less than 0.001; 95% confidence interval, 0.09-0.23 mm). Fifty of the subjects were examined twice to estimate the interobserver variability. The coefficients of variation for mean and maximum wall thickness were 10.2% and 8.9%, respectively. The two study groups were well matched and differed only in lipid levels. Thus, there is reason to believe that the difference in wall thickness can be explained by the background of familial hypercholesterolemia and the increased cholesterol levels.

Effect of short-term beta blockade on serum lipid levels and on the interaction of LDL with human arterial proteoglycans

In view of conflicting evidence suggesting that beta-blockers have an anti-atherogenic effect as well as induce a potentially atherogenic lipoprotein profile, the effects of a short term beta-blockade on serum lipoproteins were studied in 39 healthy volunteers. Because the interaction of LDL with arterial proteoglycans appears to play a role in lipoprotein accumulation during atherogenesis, the effects of metoprolol and atenolol on low density lipoprotein interaction with human aortic proteoglycans were included in the study. We could confirm that the beta-blockers caused a decrease in HDL cholesterol and an increase in triglycerides, both potentially undesirable effects. In addition, however they induced a significant decrease in the in vitro LDL affinity for arterial proteoglycans. Since there appears to be a strong association between LDL reactivity with proteoglycans and risk for myocardial infarction, this effect of the beta-blockers may be an anti-atherogenic effect which overrides other effects on the lipoprotein pattern.

Metabolic effects of controlled-release metoprolol in hypertensive men with impaired or diabetic glucose tolerance: a comparison with atenolol

In a double-blind, randomized, cross-over study with a single-blind placebo run-in period a new controlled-release (CR) formulation of metoprolol 200 mg once daily was compared with atenolol tablets 100 mg once daily in 22 patients (age 60.9 +/- 0.93 (SE) years) with primary hypertension and impaired or diabetic glucose tolerance. Each period lasted for three weeks. The two agents produced similar blood pressure 3 h as well as 24 h after drug intake. Three hours after drug intake, heart rate was lower on atenolol than metoprolol CR treatment, indicating a higher degree of beta-receptor blockade for atenolol at this point in time, when the plasma concentration of atenolol was most likely to be close to its peak. Concentrations of blood glucose, serum insulin, and serum C-peptide in the fasting state or after an oral glucose load did not differ between the active agents. HbA1c was marginally, but significantly, lower on atenolol than metoprolol CR treatment. No differences were found in serum levels of total, low density lipoprotein (LDL), and high density lipoprotein (HDL) cholesterol or apoA-I, and apoB lipoproteins or triglycerides. In comparison to the placebo run-in period, both agents showed an unexpected improvement in glucose tolerance, a decrease in HDL cholesterol and for metoprolol CR a small, but significant decrease in LDL cholesterol. Thus, treatment with metoprolol CR tablets producing even plasma levels without high peak concentrations and conventional atenolol treatment had similar effects on metabolic control in hypertensive men and abnormal glucose tolerance.

Antihypertensive effect of diet compared with drug treatment in obese men with mild hypertension

OBJECTIVE

To determine whether dietary treatment has a similar antihypertensive effect to conventional drug treatment while being superior to drugs in improving serum lipid concentrations in obese men with mild hypertension.

DESIGN

Six week run in period followed by randomisation to either diet or drug treatment groups for one year.

SETTING

Outpatient clinic in city hospital.

PATIENTS

61 Men aged 40-69 years, body mass index greater than or equal to 26, diastolic blood pressure 90-104 mm Hg when untreated. Exclusion criteria were signs of organ damage secondary to hypertension and diseases that might have interfered with compliance or with interpretation of results.

INTERVENTIONS

Dietary treatment was based on weight reduction, restriction of sodium, and decrease of excess alcohol intake (defined as greater than or equal to 250 g alcohol per week). Drug treatment used a stepped care approach with atenolol as drug of first choice.

MAIN OUTCOME MEASURES

Diastolic blood pressure less than 90 mm Hg; absolute reductions in blood pressure and serum lipid concentrations.

RESULTS

Mean body weight decreased 7.6 kg in the diet group and increased 0.9 kg in the drug treatment group (p less than 0.0001), and mean sodium excretion decreased 42 and 10 mmol/24 h respectively (p = 0.019). There was no difference in reported alcohol intake. Mean systolic blood pressure decreased 4 mm Hg in the diet group and 16 mm Hg in the drug group (p = 0.003) and diastolic blood pressure 3 and 11 mm Hg respectively (p = 0.002). Diastolic blood pressure of 90 mm Hg was attained by 29% of the diet group (nine men) and 73% (22) of those receiving drug treatment (mean difference 44%, 95% confidence interval 21 to 67%, p = 0.001). Dietary treatment produced decreases in mean serum concentrations of total and low density lipoprotein cholesterol as well as triglycerides and an increase in high density lipoprotein cholesterol concentration. In the drug treatment group the changes were in the opposite direction, and the groups differed significantly in all but total cholesterol.

CONCLUSIONS

Dietary treatment was inferior to conventional drug treatment in controlling mild hypertension but superior in lowering serum concentrations of lipids.

Apolipoprotein B in human aortic biopsies in relation to serum lipids and lipoproteins

A total of 46 patients, aged 39-71 years (mean 57.7), were studied. Forty-eight percent of the patients were hyperlipidemic and 63% had earlier suffered a myocardial infarction. Biopsies from aorta were obtained during coronary bypass surgery. Apo B was extracted from the intima by incubation of the tissue in buffer, followed by collagenase digestion. Intimal apo B was quantified in an immunoradiometric assay. There were significant correlations between total or collagenase-extractable apo B and serum cholesterol (rs = 0.39, P less than 0.01), serum triglycerides (rs = 0.33, P less than 0.05), LDL cholesterol (rs = 0.33, P less than 0.05) and serum apo B (rs = 0.37, P less than 0.05). The correlations were strongest for the collagenase-extractable apo B, while no correlations were observed for the buffer-extractable intimal apo B. No significant correlations were found between intimal apo B and serum HDL, apo A-I, smoking habits, history of hypertension or sustained myocardial infarction. Follow-up data were available for 42 of the patients, with a mean follow-up period of 35.1 months. The patients were classified according to symptoms of angina pectoris at the time of follow-up. There were significantly lower levels of serum apo A-I in the patients with poorer clinical prognosis. In a linear multiple stepwise regression analysis, apo A-I and serum LDL were significantly and independently related to clinical prognosis (R2 = 0.31).

XbaI restriction fragment length polymorphism of apolipoprotein B in Swedish myocardial infarction patients

Apolipoprotein B (apoB) is a major importance to the metabolism of lipoproteins, and there is also evidence which suggests that apoB plays a central role in atherogenesis. In order to study whether there is a link between one of the mutations of the apoB gene and premature coronary heart disease, the frequency of the XbaI RFLP for the apoB gene was analysed in 52 male myocardial infarction patients. These were compared with a control group matched for age and sex (n = 52), and a random population sample of middle-aged men (n = 106). Two alleles were identified by the presence (X2) or the absence (X1) of an XbaI cleavage site. A somewhat higher frequency of the X2 allele was seen among the patients, however there was no significant difference between patients and controls regarding the genotypes or allele frequencies. This observation does not confirm one earlier report where a higher frequency of the X1 allele was seen in myocardial infarction patients. Differences between the studied populations or epidemiological designs of the studies might explain the diverging results. Further studies are evidently needed to fully resolve the relation between the XbaI RFLP and risk of atherosclerotic disease or lipoprotein metabolism.

Lack of correlation between the apolipoprotein B XbaI polymorphism and blood lipid levels in a Swedish population

The possible connections between the apolipoprotein B (apo B) XbaI polymorphism and the serum levels of total cholesterol, triglycerides, LDL, HDL and apo B have been investigated among 187 randomly selected subjects from Gothenburg, Sweden. The interferences of age and sex on the serum lipoproteins and apo B concentrations were considered. Using multiple regression analysis, we compared the different lipid levels and the levels of apo B with the genotypes X1X1, X1X2 and X2X2 (X1 = without the XbaI restriction site, X2 = with the site), with age and with sex and with those factors combined with each other. A significantly higher concentration of serum cholesterol and LDL among men than among women was found and total serum cholesterol, LDL and apo B were positively correlated with age. The allele frequency of the XbaI polymorphism in the sample was 0.45 for the allele without the XbaI restriction site. No correlation was found between the apo B genotypes and the levels of serum lipoproteins or apo B.

Affinity of LDL to a human arterial proteoglycan among male survivors of myocardial infarction

In the present study, the hypothesis that the affinity of LDL to arterial proteoglycans might discriminate myocardial infarction patients from controls were tested. The patients were 52 men who had sustained a myocardial infarction at an age of 50 years or less and the controls, selected from a random population sample, were matched to the patients for age and sex. Serum cholesterol, triglycerides, LDL-cholesterol, HDL-cholesterol and apoB discriminated patients from controls. In addition, LDL reactivity with arterial proteoglycans was significantly higher in patients than in controls. In a multiple regression analysis, with patient or control as the dependent variable, apoB levels, LDL proteoglycan reactivity and serum triglycerides appeared as independent contributors to the regression. These observations indicate that LDL reactivity with arterial proteoglycans is a new, highly significant factor which discriminates between young myocardial infarction patients and controls.

Serum lipids and apolipoprotein levels in women with acute myocardial infarction

In this study covering more than 150,000 person-years from women younger than 55 years of age, 61 survived a first acute myocardial infarction (AMI). Of these, 59 were compared with a random sample from the same population regarding serum lipids and apolipoproteins (apo) A-I, A-II, B, and E, as well as several other cardiovascular risk factors. Mean values of serum cholesterol, triglycerides, apo B, and apo E were significantly higher and high density lipoprotein cholesterol and apo A-I were significantly lower among patients with infarction than among controls. Those who sustained and survived an AMI more often had a history of hypertension and of tobacco smoking than did the controls. Cigarette smoking, a history of hypertension, age, high serum triglycerides and apo E, as well as low levels of apo A-I, were independently and significantly associated with infarction. Sixty percent of the cases and 11% of the controls were distributed in the highest quartile of risk. A major contribution to the association with AMI was accounted for by the conventional risk factors, cigarette smoking and hypertension, as well as high serum triglycerides. In this group of relatively young women, high serum triglycerides were strongly associated with infarction, while levels of serum cholesterol were not.

Aortic intimal lipid content and serum lipoproteins in patients undergoing coronary by-pass surgery as related to clinical prognosis

Intimal lipid concentrations were determined in aortic biopsies obtained during coronary by-pass surgery. In addition serum lipoprotein and apolipoprotein levels were quantitated and their relationships to aortic intimal lipid concentrations were analysed. The possibility to use aortic intimal lipid and serum lipoprotein or apolipoprotein concentrations to predict clinical prognosis following the coronary by-pass operation was also evaluated. Intimal cholesterol, cholesterol ester, phosphatidylcholine and sphingomyelin were intercorrelated, whereas none of these lipid fractions correlated to aortic intimal triglyceride levels. Patients with hypertension had higher aortic intimal cholesterol ester levels than normotensive patients. There was a positive correlation between the number of stenosed coronary arteries and serum apo B or triglyceride levels. In addition there was a negative correlation between the number of stenosed arteries and HDL-cholesterol. Prognosis after the operation was inversely correlated to serum apo A-I levels. Our data do not, however, support the notion that aortic intimal lipid levels can be used to evaluate prognosis after coronary by-pass surgery.

Comparison of nicardipine and propranolol in the treatment of mild and moderate hypertension

In a double-blind controlled trial 22 patients with mild or moderate essential hypertension were treated with nicardipine 30 mg t.d.s. and 19 patients with propranolol 80 mg t.d.s. as monotherapy for 24 weeks. Blood pressure in both groups at the end of trial was equally and significantly reduced; systolic pressure 22.2 mmHg and diastolic pressure 15.5 mmHg in the supine position, and 24.4 mmHg and 18.4 mmHg, respectively, in the standing position in those on nicardipine, and by 23.7 and 16.2 mmHg and 28.0 and 19.2 mmHg, respectively, in the propranolol group. There was an initial increase in heart rate in the nicardipine group, but the rise was only moderate (3 beats/min supine p = 0.3219, and 7 beats/min standing, p = 0.0203) at the end of the 24 weeks. In the propranolol group heart rate was reduced markedly. Adverse effects occurred in 77% of patients on nicardipine and in 63% of those on propranolol, and there were no unexpected findings. The effects were mild in both groups and did not lead any patient to stop medication. One patient on propranolol was withdrawn from the trial because of poor blood pressure control and suspected angina pectoris after 5 weeks on active medication. There were no significant changes in blood chemistry, including lipoprotein classes. Overall, in comparison with propranolol, nicardipine was effective, well-tolerated and safe to use in the monotherapy of mild or moderate essential hypertension.

Effect of guar gum on body-weight, hunger ratings and metabolism in obese subjects

The effect of a palatable granulated guar-gum preparation (10 g twice daily) was studied in obese subjects. The acute effect of a single dose of guar gum to reduce the peak postprandial whole blood glucose levels (about 10%) was verified. Following long-term treatment, a further reduction was seen in the obese subjects with the highest postprandial glucose levels. Since the postprandial plasma insulin levels were essentially unchanged, this finding suggested an increased responsiveness to insulin. Total serum cholesterol levels were significantly reduced following long-term treatment but serum alpha-cholesterol levels, representing the high-density-lipoprotein fraction, was unchanged. Body-weight was significantly reduced during guar-gum treatment even though the patients were asked to maintain their normal dietary habits. Daily hunger ratings recorded for up to 10 weeks showed that guar gum reduced hunger significantly better than commercially available bran taken in the same way. Thus, guar gum seemed to influence carbohydrate and lipid metabolism in a beneficial way in obese subjects. The reduction in hunger would offer an additional benefit to these patients.

Effect of a modified guar gum preparation on glucose and lipid levels in diabetics and healthy volunteers

Six healthy volunteers and 17 diabetics (6 insulin-dependent and 11 diet- and tablet-treated) were treated with a special processed, palatable guar gum (10 g b.i.d. immediately before meals) for periods of one or three weeks or, in some cases, up to 13 weeks. A standardized test meal was given to study the effect of the fiber on postprandial glucose levels. Ten g guar was stirred in water and taken immediately before the test meal. The postprandial blood glucose levels were similar in the healthy volunteers but significantly lower in the diabetics following treatment with guar for one and three weeks, respectively. Furthermore, the fasting blood glucose levels were significantly lower in the diabetics after three, but not one, weeks of treatment. The lower postprandial glucose levels were coupled with attenuated and delayed insulin levels in accordance with an effect of guar gum on the rate of carbohydrate absorption. The cholesterol levels were on average reduced with 14% in the diabetics following three weeks' treatment with guar. The higher the initial cholesterol level, the greater the reduction in cholesterol; 26% reduction was achieved in four patients with initial levels above 7 mM. The alpha-lipoprotein cholesterol levels were not significantly changed, thus an increase in the alpha-lipoprotein cholesterol/total serum cholesterol ratio was obtained. Neither plasma triglycerides nor body weights altered during treatment. The reported side-effects were as expected and were usually mild and transient (e.g. increased flatulence). The data show that guar gum also reduces postprandial glucose levels on a long-term basis and may improve the diabetic control. Additionally, treatment with this fiber leads to a concentration-dependent decrease in cholesterol levels.