Deletion polymorphism of angiotensin-converting enzyme gene is associated with postprandial hyperglycaemia in individuals undergoing general check-up.

1. Deletion polymorphism, DD, of the angiotensin-converting enzyme (ACE) gene is reported to be related to cardiovascular disease, which is frequently based on insulin resistance. 2. To clarify the relationship between the ACE genotype DD and plasma glucose increases after an oral glucose load, we performed 75 g oral glucose tolerance test (OGTT) in 301 nondiabetic men (age range 30-60 years) undergoing general check-up. 3. Insertion/deletion (I/D) polymorphism of the ACE gene was explored using a polymerase chain reaction. The frequency of the II, ID and DD genotypes was 0.43, 0.43 and 0.14, respectively. 4. There were no differences in baseline clinical characteristics between subjects with each ACE genotype. 5. The mean (+/- SEM) plasma glucose level at 60 min of the OGTT was significantly higher in subjects with the DD genotype (170.8 +/- 6.9 mg/dL) than in subjects with either the II or ID genotype (mean value for two groups 156.6 +/- 2.7 mg/dL; P < 0.05). Moreover, the mean percentage change of plasma glucose after 60 min of the OGTT, a marker of plasma glucose increase, was significantly higher in individuals with the DD genotype than in individuals with either the II or ID genotypes. 6. In contrast, the mean fasting plasma glucose level, the plasma glucose level at 120 min, the glucose response area and the fasting insulin level were not different between individuals with the DD genotype and individuals with other genotypes. 7. In conclusion, subjects with the DD genotype showed transiently higher levels of plasma glucose after an oral glucose load than subjects with other genotypes. Further studies are required to determine whether the association between ACE genotype and postprandial hyperglycaemia influences the incidence of cardiovascular disease and diabetes mellitus.

Relationship among risk factors of atherosclerosis, leukocyte count, and soluble intercellular adhesion molecule-1.

We investigated the effects of risk factors of atherosclerosis on soluble intercellular adhesion molecule-1 (sICAM-1) concentration and leukocyte count by using multivariate statistical analysis. The subjects were 90 people who were hospitalized for a complete check-up examination. Eight risk factors were selected as candidates for predictor variables: age, body mass index (BMI), uric acid, glycohemoglobin A1c, number of cigarettes smoked daily, total cholesterol, triglyceride, and high density lipoprotein (HDL)-cholesterol. The predictor variables were selected using a stepwise method, [criterion variable - predictor variable (standardized regression coefficient)]; sICAM1 - age (0.1859), number of cigarettes (0.2558), triglyceride (0.2447); leukocytes - number of cigarettes (0.2827), triglyceride (0.2526), HDL-cholesterol (-0.2800); stab leukocytes - number of cigarettes (0.2460); segmented leukocytes - glycohemoglobin A1c (0.1495), number of cigarettes (0.2716), HDL-cholesterol (-0.3254); lymphocytes - BMI (0.2639), number of cigarettes (0.1495), triglyceride (0.3520); monocytes - glycohemoglobin A1c (0.2617). These findings indicated that the risk factors of atherosclerosis may influence sICAM1 concentration and leukocyte count.

[Glucose tolerance and insulin resistance in the elderly].

Glucose tolerance is reported to be impaired in the elderly, and this is said to be mainly due to a decrease in insulin sensitivity (insulin resistance). Insulin resistance is known to be associated with atherosclerosis and coronary artery disease. To clarify whether or not age-dependent changes in glucose tolerance and insulin sensitivity are risk factors for coronary artery disease, as they are in the case of the insulin resistance syndrome, we studied age-dependent changes in glucose tolerance, insulin sensitivity, blood pressure, and serum lipids in a large number of subjects who underwent annual health check-ups, and then studied the relationships between coronary artery disease and aging, insulin sensitivity, and other risk factors in subjects who underwent coronary angiography. Aging was associated with an increased prevalence of noninsulin-dependent diabetes mellitus and impaired glucose tolerance; even in subjects with normal glucose tolerance, plasma glucose levels during an oral glucose tolerance test were significantly higher in the elderly. Insulin sensitivity, as assessed by the ratio of the sum of the plasma glucose divided by the sum of the serum insulin during the test (sigma PG/sigma IRI), was significantly lower in subjects over 60 years old than in younger subjects. Age-dependent impairment of insulin sensitivity and glucose tolerance was associated with increased blood pressure and serum cholesterol levels, but not with changes in boy mass index or serum triglyceride levels. As an independent variable, aging, but not insulin sensitivity, was related to the severity of coronary artery disease. These data suggest that aging is associated with glucose intolerance, insulin resistance, and an increased risk of coronary artery disease, but that the effect of aging on coronary artery disease cannot be explained by insulin resistance alone. Other factors, such as glucose intolerance and increased blood pressure, in addition to insulin resistance, appear to be responsible of the increased risk for coronary artery disease in the elderly.

Polymorphism of the apolipoprotein E and angiotensin-converting enzyme genes in Japanese subjects with silent myocardial ischemia.

The apolipoprotein epsilon4 allele and homozygous deletion allele (DD) of the angiotensin-converting enzyme gene are reported to be associated with an increase in the incidence of ischemic heart disease. In this study, we examined whether the apolipoprotein epsilon4 genotype and angiotensin-converting enzyme/DD allele are associated with silent myocardial ischemia. We screened 3920 subjects undergoing general checkups who no symptoms of ischemic heart disease. Seventy subjects (2 percent) showed ischemic ST-segment depression during the double two-step exercise test. One hundred and twenty control subjects without ischemic ST-segment depression were recruited from the same population and matched for sex, age, and blood pressure. We performed genotyping of the apolipoprotein E gene (epsilon2, epsilon3, and epsilon4) and angiotensin-converting enzyme gene (I and D) using polymerase chain reaction-restriction fragment length polymorphism and polymerase chain reaction, respectively. Allele frequently of epsilon4 of the apolipoprotein E gene was higher in the ischemic group (11 percent) than the nonischemic group (5 percent) (chi2 = 5.35, P < .05), but there was no significant association between the allele or the genotype frequency of the angiotensin-converting enzyme gene and the incidence of ischemic ST-segment depression. Furthermore, stepwise multiple regression analysis also revealed that total cholesterol level and epsilon4 genotype were predictors of ischemic change in the exercise tolerance test (chi2 = 12.8, P < .005, R(2) = .051). These results suggest that the apolipoprotein epsilon4 allele is an independent genetic risk factor for silent myocardial ischemia in Japanese subjects.

Mass screening for complete deficiency of thyroxine-binding globulin in adult Japanese by comprehensive health examination.

The incidence of complete thyroxine-binding globulin (TBG) deficiency (TBG-CD) was determined for a Japanese population from a comprehensive health examination, in which a T3 resin uptake test of the upper 5% (78 subjects from among 1,589 men) was the screening line for TBG-CD. Further analysis of the known mutation in TBG-CD gene of the Japanese population (reported as TBG-CDJ with codon 352 deletion) was performed on 72 subjects, and three were found to have TBG-CDJ, two of whom were siblings. Only those three subjects had a serum TBG concentration of less than 5 mg/l. The six subjects for whom the DNA analysis was not performed, did not have a serum TBG level of less than 5 mg/l. From these findings, the gene frequency of TBG-CDJ was calculated to be 0.13%. The incidence of TBG-CDJ in the total Japanese population is suggested to be 0.09%.

[Neuron specific enolase-producing IgD multiple myeloma with high serum amylase activity].

A 68-year-old man who was admitted to our hospital because of general fatigue and anorexia. He was diagnosed as suffering from neuron specific enolase (NSE)-producing IgD-lambda type multiple myeloma with high activity of serum amylase, based on the detection of monoclonal IgD-lambda M-protein in the serum and urine, markedly high activities of salivary-type amylase and NSE in the serum, and immunohistochemical evidence of NSE and IgD in the myeloma cells. After two courses of alpha-IFN and VMCP chemotherapy, serum IgD, amylase and NSE decreased to normal levels. These observations indicate that NSE was ectopically produced by myeloma cells.

A new mitochondrial DNA mutation associated with non-insulin-dependent diabetes mellitus.

Mitochondria play an important role in glucose-induced insulin secretion in pancreatic beta cells. We therefore examined whether patients with NIDDM exhibit genetic variability in mitochondrial DNA (mtDNA), a candidate gene for NIDDM. We sequenced mtDNA in the region encoding tRNALeu and the adjacent region in several diabetic patients with clinical features suggesting mitochondrial DNA mutations. We found a new point mutation at position 3316 that leads to an amino acid change in the ND-1 protein. The frequency of the mutation was screened with PCR-RFLP in 295 NIDDM patients and 406 controls. We found ten NIDDM patients (3.4%) harbored the mutation. Although 4 control subjects had the mutation, the frequency was significantly higher in the NIDDM patients than in the control subjects (p = 0.02). These results suggest that the 3316 mutation is associated with NIDDM.

[The effect on age for the relationship between hypertension and glucose intolerance].

Recently, high frequencies of glucose intolerance and insulin resistance have been reported in patients with hypertension. However, both blood pressure and glucose tolerance are influenced by age. To investigate the effect of age on the interaction between blood pressure and glucose tolerance, we analyzed blood pressure and glucose tolerance in otherwise healthy subjects (n = 576) who underwent an oral glucose tolerance test and blood pressure measurement as a part of a healthy care program. The prevalence of DM and IGT were significantly higher in the hypertensive group than in the normotensive group. When the subjects were divided into three groups according to their age (less than 50 years old, between 50 and 60 years old and more than 60 years old), the prevalence of glucose intolerance (DM or IGT) was significantly higher in the hypertensive group than in the normotensive group in subjects under 50 years old, but not in subjects between 50 and 60 years old or over 60 years old. In the subjects classified as having normal glucose tolerance, the incremental area of glucose under the curve of 75g-OGTT was significantly higher in the hypertensive group than in the normotensive group. These data suggest that hypertension is associated with glucose intolerance in Japanese population and that age significantly affects this interaction.

Hereditary complete thyroxine-binding globulin deficiency: identification by T3 resin uptake test and DNA analysis.

Complete thyroxine-binding globulin deficiency (TBG-CD) was uncovered in a subject receiving a comprehensive health examination. The subject had an abnormally high T3 resin uptake. A family study showed that the TBG abnormality had been inherited by X-chromosome linkage. Genetic analysis revealed single nucleotide deletion, common among Japanese with TBG-CD, from the allele specific amplification of the TBG genes of the family.

Analysis of the apolipoprotein B3' hypervariable region in patients with essential hypertension.

1. The typing of the apolipoprotein B 3' hypervariable region was investigated in hypertensive and normotensive subjects using rapid typing of a variable number of tandemly repeated short DNA sequences (VNTR) by the polymerase chain reaction. 2. In the DNA samples of 89 normotensive and 99 hypertensive patients, 13 different-sized alleles were detected. The most frequent allele has 35 repeat units in both groups with frequencies of 0.624 and 0.596 in normotensive and hypertensive patients, respectively. Frequency distribution of 13 alleles was similar in both groups. 3. These results demonstrate no association between the apolipoprotein B gene polymorphism and essential hypertension.

Clinical and basic aspects of an anorexiant, mazindol, as an antiobesity agent in Japan.

The Japanese Mazindol study group investigated the action of an anorexiant, mazindol, and found that it reduced food intake by directly suppressing neurons in the lateral hypothalamus, inhibited gastric acid secretion, increased motor activity, decreased glucose absorption, and inhibited insulin secretion. It thus appears that the main effect of mazindol is to decrease food intake through suppressing feeding centers in the hypothalamus. A multicenter open study of mazindol in Japan revealed that loss of body weight and relative body weight in 14 wk were 4.6 kg and 9.2%, respectively, with suppression of appetite in the majority of obese patients. A multicenter double-blind study demonstrated that mazindol was superior to the placebo in the treatment of simple obesity. We also suggest that mazindol is effective in the maintenance of reduced body weight after obesity therapy and in the treatment of obesity-related diseases such as diabetes, hypertension, or hyperlipidemia.

Clinical evaluation of delapril in Japan. Report from the Japan Study Group on Delapril.

Delapril, a new angiotensin converting enzyme (ACE) inhibitor discovered in the laboratory of Takeda Chemical Industries, Ltd., is the result of drug design based on the structure-activity relationships of ACE inhibitors. Delapril is an antihypertensive agent with a relatively long duration of action and no SH moiety in its structure. Following administration, it is converted into two active metabolites. Delapril effectively lowered blood pressure in 73% of 1,008 patients with hypertension during clinical trials in Japan. Efficacy rates were 73% for essential hypertension, 85% for renal hypertension, and 80% for renovascular hypertension. Excellent hypotensive response was observed in all age groups, from young to elderly patients. Side effects during administration of delapril, based on subjective evidence, were reported in 80 out of the 1,008 cases (7.9%). The main symptoms included orthostatic dizziness (1.7%), dizziness (1.3%), and nausea (1.1%). Dry cough, which has attracted attention in recent years as a side effect of ACE inhibitors, was reported at a low incidence of 1.1%. In a double-blind, controlled study in patients with mild to moderate essential hypertension in which captopril served as a positive control, delapril showed superior hypotensive effect and greater safety. Data derived from the Japan Study Group on Delapril indicate that this ACE inhibitor has excellent hypotensive effects and a high level of safety. It is suitable as a first-line drug in both monotherapy and combined therapy.

Increased frequency of 6-thioguanine-resistant peripheral blood lymphocytes in Werner syndrome patients.

The frequency of spontaneous 6-thioguanine (TG)-resistant peripheral blood lymphocytes in five unrelated Werner syndrome (WS) patients was determined using an autoradiographic labeling assay. The average frequency of TG-resistant lymphocytes was eightfold higher in WS patients than in sex- and age-matched normal control donors. This finding and previous identification of increased spontaneous chromosomal rearrangements and deletions in WS cells or cell lines suggest that WS is a human genomic instability or mutator syndrome.

Contribution of the baroreflex afferent nerves to the production of vasoconstricted hypertension in volume-expanded dogs.

Dextran in lactated Ringer's solution (20 ml/kg) was infused for 1 hour into anesthetized dogs with sinoaortic denervation and vagotomy (deafferentation; n = 10) and dogs treated with hexamethonium (de-efferentation; n = 13) to compare with our previous observation in dogs with an intact autonomic nervous system (control, n = 34). During the infusion, increase in blood pressure associated with increase in cardiac output was observed in all three groups. The increases in blood pressure were larger in the two groups with an impaired autonomic nervous system. In the recovery period, the control dogs and the hexamethonium-treated dogs showed gradual increases in total peripheral resistance and in vasoconstricted hypertension 3 hours after stopping the infusion. In contrast, the dogs with sinoaortic denervation and vagotomy did not show any increase in total peripheral resistance. The vasoconstricted groups showed peaks of natriuresis soon after the infusion, not 3 hours after the infusion when vasoconstriction was observed, although the dogs with deafferentation did not show a significant increase in natriuresis. Norepinephrine (0.5 micrograms/kg) was administered intravenously before and after volume expansion, and the pressor responses in the three groups after volume expansion were enhanced similarly (143%, 128%, and 136%, respectively). These results indicate that the afferent signals from peripheral vessels to the brain contribute to the production of vasoconstricted hypertension after acute volume expansion and that the vasoconstriction is independent of pressor hypersensitivity and is dissociated in time from the natriuresis.

High plasma levels of cortisol in patients with senile dementia of the Alzheimer's type.

Plasma cortisol levels and other factors including thyroid hormone in patients with Alzheimer's type (n = 10), vascular type (n = 10) or mixed type (n = 10) senile dementia were compared with those in non-demented senile controls (n = 10). Plasma cortisol levels at 8:00 a.m. in Alzheimer's type dementia and mixed type dementia were 17.3 +/- 4.3 micrograms/dl (mean +/- SD) and 15.6 +/- 2.3 micrograms/dl, respectively. These values were significantly higher (p less than 0.005 and p less than 0.01) than those found in the control subjects (12.0 +/- 3.1 micrograms/dl). Plasma cortisol levels in vascular-type dementia (14.4 +/- 6.3 micrograms/dl) did not differ significantly from those in the controls. Plasma ACTH in senile dementia of the Alzheimer's type was lower, but not significant as compared with that in normal controls. In three subgroups of senile dementia and normal controls, plasma cortisol levels inversely correlated significantly with the degree of cognitive function. Plasma levels in TSH-thyroid system and blood pressure did not show any significant change in three types of senile dementia. These data suggest that senile dementia of the Alzheimer's type accompanies relatively and primarily high plasma cortisol levels and this may associate with cognitive dysfunction in Alzheimer's type senile dementia.

Effects of very-low-calorie diet weight reduction on glucose tolerance, insulin secretion, and insulin resistance in obese non-insulin-dependent diabetics.

We put 12 obese subjects on a very-low-calorie diet (VLCD) and observed how their weight loss affected their glucose tolerance. Seven had non-insulin-dependent diabetes and five did not. They consumed 1000 kcal/day for at least 1 week, then 420 kcal/day for 4 weeks, and 1000 kcal/day thereafter. VLCD improved glucose tolerance and insulin response to a glucose load in the diabetics and did not affect these parameters in the non-diabetics. It did not change insulin responsiveness to intravenous glucagon in either group. Both groups showed improved insulin resistance, as measured by an insulin suppression test. Regression analysis showed that insulin resistance correlates well with obesity and glycemic control. Weight reduction did not change hepatic insulin extraction. Thus, the improvement in glucose tolerance by some of the diabetics seems to have arisen from improvements in their insulin resistance and insulin response to a glucose load. Insulin resistance improved because of weight reduction and subsequent improvements in glycemic control.