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Biomedical subjects

T Rönnemaa

Publications and source records attributed to T Rönnemaa.

At least 73 records · Page 4Linked to original sources
PubMed1999

Significance of graft occlusion and coronary atherosclerosis 5 years after coronary artery bypass grafting. A quantitative angiographic study with serial exercise testing.

OBJECTIVE: To evaluate the relative importance of graft occlusions and progression of atherosclerosis in coronary arteries as causes of the occurrence of angina pectoris and impairment of physical performance 5 years after coronary artery bypass surgery. DESIGN: A 5-year follow-up study. SETTING: University hospital in south-western Finland. SUBJECTS: Altogether, 174 consecutive electively operated bypass patients. MAIN OUTCOME MEASURES: Serial clinical evaluation and bicycle exercise tests (pre-operatively, at 6 months, and at 1 and 5 years). Quantitative coronary angiography pre-operatively and 5 years after the surgery. RESULTS: Subjects with patent grafts had fewer angina pectoris symptoms at the 5-year follow-up (24 vs. 52%, P = 0.001) and were treated less frequently with long-acting nitrates (3 vs. 15%, P = 0.037) than subjects with graft occlusions. Fewer of them were in classes II-III of the functional classification of the Canadian Cardiovascular Society (39 vs. 74%, P = 0.001). The exercise test was interrupted less often because of chest pain (23 vs. 41%, P = 0.03) and improvement in exercise test variables during the follow-up period was significantly greater in subjects with patent grafts (P<0.002). Amongst patients without graft occlusions, those with new > or =50% diameter stenoses in coronary arteries were more often in functional classes II-III (59 vs. 32%, P = 0.03) than those without new stenoses, but the groups were similar with respect to angina pectoris and exercise tests variables. In patients with graft occlusions, those with and without new > or =50% diameter stenoses were similar with respect to functional class, angina pectoris and exercise test variables. CONCLUSIONS: Angina pectoris and impairment of physical capacity 5 years after coronary artery bypass grafting are mainly due to occlusion of bypass grafts and not to progression of atherosclerosis in coronary arteries.

Aged↗
PubMed1999

Factors predicting lower extremity amputations in patients with type 1 or type 2 diabetes mellitus: a population-based 7-year follow-up study.

OBJECTIVES: The aim of the study was to find factors predicting lower extremity amputation in patients with type 1 or type 2 diabetes mellitus through a 7-year follow-up period. DESIGN: Follow-up study. SUBJECTS: Altogether 733 diabetic patients. aged 10-79 years, were drawn from the national drug reimbursement register. METHODS: At baseline, the patients underwent a podiatric, circulatory and neurophysiological examination. Seven years later a follow-up study was performed based on clinical and register data. Patient data for those who died during the follow-up were collected from hospital records and death certificates. All amputations were recorded. The patients with amputation were compared with the other patients and also, in a case-control manner, by taking three nonamputated patients matched by sex, type of diabetes, and age for each patient with amputation. RESULTS: The number of amputations was 25 in the sample. Compared with all patients without amputation, patients with amputation differed in altogether 24 variables concerning diabetes and its complications. Compared with the matched non-amputated patients, the amputated patients had longer duration of diabetes, lower ankle/brachial pressure index (ABI), more often history of retinopathy, nephropathy, and hypertension, more often visual handicap, elevated serum creatinine level, abnormal neurophysiological indices and electrophysiological findings. In the logistic regression analysis, vibration perception threshold, low ABI, history of retinopathy, visual handicap, and male sex were independently associated with lower extremity amputation. CONCLUSIONS: Lower extremity amputations were strongly associated with retinopathy, nephropathy, and neuropathy. The presence of any of these complications should lead to intensified actions in order to prevent amputations. As far as arterial circulation is concerned, claudication or absent peripheral pulses were not good predictors of amputation, whereas low ABI, despite its known weaknesses, was a reliable indicator of future amputation.

Adolescent↗
PubMed1999

Serum cholesterol ester fatty acids in 7- and 13-month-old children in a prospective randomized trial of a low-saturated fat, low-cholesterol diet: the STRIP baby project. Special Turku coronary Risk factor Intervention Project for children.

To evaluate changes that occur in serum cholesterol ester fatty acid composition during the transition from typical infant feeding to a more adult type of nutrition, this study compared the effects on serum cholesterol ester fatty acids of breast milk or formula at the age of 7 mo with effects caused by 6-mo dietary intervention in 137 children. The intervention [Special Turku coronary Risk factor Intervention Project for children (STRIP baby project)] aimed at a reduction of saturated fat intake to 10% of energy after the age of 1 y without purposefully influencing total fat intake. Nutrient intakes were calculated from 3-d food records. At the age of 7 mo, i.e. before dietary education began, milk type markedly influenced dietary and serum cholesterol ester fatty acid composition (mean serum cholesterol ester 16:0 in breastfed vs formula-fed infants, 13.7% vs 12.0%, respectively, p < 0.001; serum cholesterol ester 18:2n-6 50.6% vs 57.6%, p < 0.001). At the age of 13 mo the calculated fat intake of the intervention and control children differed markedly but serum cholesterol ester fatty acid compositions in all children resembled closely those measured in 7-mo-old breastfed infants, e.g. at the age of 13 mo the relative proportions of 18:2n-6 were 49.9% and 51.1% in previously formula-fed intervention and control children, respectively, and 50.3% and 50.1% in previously breastfed intervention and control children, respectively. In conclusion, serum cholesterol ester fatty acid composition reflected differences in dietary fat quality (breast milk or formula) at the age of 7 mo, whereas dietary intervention as applied in the STRIP baby project had only a minimal effect.

Breast Feeding↗
PubMed1999

Influence of dietary fat on the nutrient intake and growth of children from 1 to 5 y of age: the Special Turku Coronary Risk Factor Intervention Project.

BACKGROUND: Excessive decreases in fat intake in young children have been linked with low intakes of energy and nutrients and possible growth failure. OBJECTIVE: We evaluated nutrient intakes and growth of healthy children with different fat intakes during the first 5 y of life. DESIGN: In the Special Turku Coronary Risk Factor Intervention Project (STRIP), 7-mo-old children were randomly assigned to an intervention aimed at reduced consumption of saturated fat and cholesterol (n = 540) or to a control group (n = 522). This analysis comprises data for children for whom > or = 6 of 8 possible 3-4-d food records were available (n = 730; 353 females). Children were divided according to fat intake pattern (percentage of energy) between the ages of 13 mo and 5 y into groups with continuously high fat intake (5% of children), increasing fat intake (5%), continuously low fat intake (5%), decreasing fat intake (5%), and average fat intake (80%). Children's energy and nutrient intakes and growth were then compared by analysis of variance. RESULTS: Fat intake at 13 mo of age was particularly low (21% of energy) in the increasing fat intake group and in the continuously low fat intake group (22% of energy at 13 mo; 26% of energy at 5 y). Growth of children in all 5 fat intake groups, however, was not significantly different throughout the study period. Intakes of vitamins and minerals, except of vitamin D, met recommended dietary allowances in all fat intake groups. CONCLUSION: Nutrient intakes and growth were not significantly different in children whose fat intake patterns differed between 13 mo and 5 y of age.

Analysis of Variance↗
PubMed1999

Large-artery elastic properties in young men : relationships to serum lipoproteins and oxidized low-density lipoproteins.

Measures of arterial elasticity have been proposed as surrogate markers for asymptomatic atherosclerosis. We investigated the relations of serum lipoproteins, oxidized low-density lipoprotein (ox-LDL), and familial hypercholesterolemia (FH) to arterial elasticity among young men. As a marker of arterial elasticity we measured compliance in the thoracic aorta by using magnetic resonance imaging and in the common carotid artery by using ultrasound. LDL diene conjugation was used as a marker of ox-LDL. In study I, 25 healthy men (aged 29 to 39) were classified into 2 extreme groups according to previously measured high-density lipoprotein cholesterol to total cholesterol ratio (HDL-C/TC ratio). In study II, the healthy men were used as controls for 10 age matched asymptomatic patients with FH. In healthy men, the group with low HDL-C/TC ratio had decreased carotid artery compliance (2. 3+/-0.4% versus 1.9+/-0.5%/10 mm Hg, P=0.034). In univariate analysis, the compliance of the carotid artery associated with ox-LDL (r =-0.49, P=0.016) and HDL-C/TC ratio (r=0.41, P=0.040). In multivariate regression analyses, ox-LDL was the only independent determinant for compliance of the carotid artery (P=0.016). Aortic elasticity was not related to standard lipid variables, but the compliance of the ascending aorta associated with ox-LDL (r=-0.44, P=0.030). In FH patients, arterial elasticity was similar to that in controls. We conclude that elasticity of the common carotid artery is affected by serum lipid profile in young men. The current study demonstrates for the first time an in vivo association between ox-LDL and arterial elasticity suggesting that oxidative modification of LDL may play a role in the alteration of arterial wall elastic properties.

Adult↗
PubMed1999

Poor glycemic control predicts coronary heart disease events in patients with type 1 diabetes without nephropathy.

Patients with type 1 diabetes mellitus, especially those with nephropathy, are at increased risk for coronary heart disease (CHD). However, information on the predictive value of cardiovascular risk factors and the degree of hyperglycemia with respect to CHD events in patients with type 1 diabetes without nephropathy is still incomplete. Therefore, we performed a prospective study on risk factors for CHD in patients with type 1 diabetes free of clinical nephropathy. At baseline examination, cardiovascular risk factor levels of CHD were determined in 177 patients with type 1 diabetes (87 men and 90 women), age 45 to 64 years at baseline and >/=30 years at the time of diagnosis of diabetes. These patients were followed up to 7 years with respect to CHD events. Altogether, 20 patients with type 1 diabetes (13 men [7.3%] and 7 women [3.9%]) died of CHD and 28 patients with type 1 diabetes (17 men [9.6%] and 11 women [6.2%]) had a serious CHD event (death from CHD or nonfatal myocardial infarction). In multivariate Cox regression analysis, a previous history of myocardial infarction (hazard ratio [HR] and its 95% confidence interval, 8.0 [3.1 to 21.0], P<0.001), high glycohemoglobin A1 (>10.4%, the highest tertile, HR 5.4 [1.4 to 20.4], P=0.013), and the duration of diabetes (>16 years, the highest tertile, HR 4.2 [1.3 to 12.9], P=0.013) were the only variables associated with CHD death even after adjustment for other cardiovascular risk factors. These variables also predicted the incidence of all CHD events. Our results indicate that poor metabolic control is a strong predictor of CHD events in patients with late-onset type 1 diabetes without nephropathy, independently of other cardiovascular risk factors.

Aged↗
PubMed1999

Bone mineral density in patients with type 1 and type 2 diabetes.

OBJECTIVE: To assess the effect of type 1 and type 2 diabetes and insulin treatment on bone mineral density (BMD) in middle-aged and elderly men and women. RESEARCH DESIGN AND METHODS: We measured BMD and evaluated known determinants of osteoporosis in 56 type 1 and 68 type 2 diabetic patients and 498 nondiabetic community control subjects. All patients, aged 52-72 years, developed diabetes after the age of 30 years (i.e., after achievement of peak bone mass) and were treated with insulin. BMD was measured at the proximal femur with dual-energy X-ray absorptiometry. RESULTS: Among both sexes, BMD values were significantly lower in type 1 diabetic patients than in type 2 diabetic patients or the control subjects. When adjusted for age and BMI, the differences between type 1 diabetic patients and control subjects remained essentially unchanged in both sexes, whereas the differences between type 1 and type 2 diabetic subjects were significant only in men. After further adjustments for confounding factors, the average BMD values were still lower in type 1 diabetic subjects than in type 2 diabetic subjects although with lesser significance. Past low-energy fractures were more common in type 1 diabetic women than in type 2 diabetic women. CONCLUSIONS: The lower BMD in type 1 versus type 2 diabetic patients and control subjects probably results from more rapid bone loss after the onset of type 1 diabetes. This cannot be explained by insulin treatment, which was prescribed for both types of patients. Because the causes of low BMD in type 1 diabetes are unknown, these patients should be evaluated for the risk of osteoporosis and related fractures and offered appropriate preventive measures.

Age of Onset↗
PubMed1999

Cardiovascular disease risk factors in young children in the STRIP baby project. Special Turku coronary Risk factor Intervention Project for children.

Introducing nutritional principles of preventive cardiology to the care of young children may improve permanently adherence to a low-saturated-fat, low-cholesterol diet later in life. This approach has not been readily adapted because of worries of the possible effects of such a diet on the growth and development of children. In the STRIP baby project, 1062 infants were randomized at 7 months of age into an intervention group (n = 540) or a control group (n = 522). The counselling of the intervention children aimed at a fat intake of 30% of energy after the age of 1 year and to a 1:1:1 ratio in saturated:monounsaturated:polyunsaturated fat intake. Dietary intake, growth and serum lipid concentrations were monitored in the children regularly through the first years of life. The intake of total fat, saturated fat and cholesterol were lower and the intake of polyunsaturated fat and the ratio of polyunsaturated to saturated fat (P/S) in the diet were higher in the intervention children than in the controls. During the first 3 years of the trial, the serum cholesterol concentration was 3-6% lower in the intervention children than in the controls (95% CI for the mean difference between groups from -0.27 to -0.12 mmol/L). No differences in the growth of the children were observed between the groups. We conclude that repeated individualized counselling aiming at reduced consumption of saturated fat combined with regular follow-up is effective and does not restrict the growth of children.

Cardiovascular Diseases↗
PubMed1998

Mortality from coronary heart disease in subjects with type 2 diabetes and in nondiabetic subjects with and without prior myocardial infarction.

BACKGROUND: Type 2 (non-insulin-dependent) diabetes is associated with a marked increase in the risk of coronary heart disease. It has been debated whether patients with diabetes who have not had myocardial infarctions should be treated as aggressively for cardiovascular risk factors as patients who have had myocardial infarctions. METHODS: To address this issue, we compared the seven-year incidence of myocardial infarction (fatal and nonfatal) among 1373 nondiabetic subjects with the incidence among 1059 diabetic subjects, all from a Finnish population-based study. RESULTS: The seven-year incidence rates of myocardial infarction in nondiabetic subjects with and without prior myocardial infarction at base line were 18.8 percent and 3.5 percent, respectively (P<0.001). The seven-year incidence rates of myocardial infarction in diabetic subjects with and without prior myocardial infarction at base line were 45.0 percent and 20.2 percent, respectively (P<0.001). The hazard ratio for death from coronary heart disease for diabetic subjects without prior myocardial infarction as compared with nondiabetic subjects with prior myocardial infarction was not significantly different from 1.0 (hazard ratio, 1.4; 95 percent confidence interval, 0.7 to 2.6) after adjustment for age and sex, suggesting similar risks of infarction in the two groups. After further adjustment for total cholesterol, hypertension, and smoking, this hazard ratio remained close to 1.0 (hazard ratio, 1.2; 95 percent confidence interval, 0.6 to 2.4). CONCLUSIONS: Our data suggest that diabetic patients without previous myocardial infarction have as high a risk of myocardial infarction as nondiabetic patients with previous myocardial infarction. These data provide a rationale for treating cardiovascular risk factors in diabetic patients as aggressively as in nondiabetic patients with prior myocardial infarction.

Case-Control Studies↗
PubMed1998

Reducing snacks when switching from conventional soluble to lispro insulin treatment: effects on glycaemic control and hypoglycaemia.

The lack of significant improvement in HbA1c during insulin lispro treatment in previous studies may have been due to inadequate dietary adjustments. We tested whether reduction of snacks and a compensatory increase in main meals results in improved metabolic control when switching to lispro treatment. One hundred and forty-one Type 1 diabetic patients, mean +/- SD age 36 +/- 9 years, diabetes duration 14 +/- 10 years, had two daily NPH injections throughout the study. After a baseline visit, the patients used conventional soluble insulin preprandially thrice daily for 12 weeks. Thereafter they were switched to lispro insulin and advised to transfer > or =50% of their snack carbohydrates to preceding main meals. Mean HbA1c at baseline was 8.05%. After the conventional period and the 12-week lispro period, HbA1c was 7.81 and 7.70% (p = 0.088), respectively. In those patients who diminished their snacks as advised (n = 67), HbA1c decreased from 7.91 to 7.66% (p = 0.014) during lispro, whereas no change was observed in patients not compliant with the dietary change. The number of hypoglycaemic episodes was lower during lispro period (blood glucose <2.5 mmol l(-1): 1.43 vs 2.19 episodes, p = 0.004; symptomatic nocturnal hypoglycaemia 1.16 vs 1.67 episodes, p<0.001). When switching from conventional soluble to lispro insulin, reduction of snack carbohydrates is safe and results in slightly improved HbA1c in patients who are fully compliant with the dietary change.

Adolescent↗
PubMed1998

Serum leptin and longevity.

There are changes in the ability to regulate energy balance and caloric intake with aging. Consequently, we investigated whether human aging modifies the levels of serum leptin, a novel hormone implicated in the regulation of energy balance. We studied 268 Caucasian men and women aged 22-85 years, and divided them into groups with mean ages of 30, 40, 50, 65, 75, 80 and 85 years. Fasting serum leptin concentrations were determined by radioimmunoassay. Subjects aged 65 or older were followed for five years after the blood sampling. There were no statistically significant differences in fasting serum leptin concentrations across different age groups in females (p = 0.090). Fasting serum leptin concentrations were also similar in different age groups in males, except that males in the 30-year age group had lower serum leptin levels than males in the 75-year age group (p = 0.042). Leptin levels were 2-3 fold higher in females than in males in each age group (p < 0.005 except p = 0.063 in the 75-year age group). Elderly women, who lived longer, had 47% higher (p < 0.05) serum leptin concentrations, and 17% higher (p < 0.001) BMI than the women who died within five years of blood sampling. Leptin levels were not statistically different in these women after adjusting for BMI. Thus, aging has no apparent effect on serum leptin levels in women or men, and the gender differences in leptin is present also in the older age groups. Higher leptin concentrations in the females who live longer may reflect a better nutritional status, and a greater adipose tissue mass rather than a primary factor for survival.

Aged↗
PubMed1998

Insulin resistance characterizes glucose uptake in skeletal muscle but not in the heart in NIDDM.

Skeletal muscle insulin resistance and coronary heart disease (CHD) often precede non-insulin-dependent diabetes mellitus (NIDDM). A recent study showed the myocardium of patients with CHD to be insulin resistant, independent of blood flow. We determined whether myocardial insulin resistance is a feature of NIDDM patients with no CHD. Skeletal muscle and myocardial glucose uptake were determined in 10 patients with NIDDM and 9 age- and weight-matched normal men of similar age and body mass index men using [18F]-2-fluoro-2-deoxy-D-glucose and positron emission tomography under normoglycaemic hyperinsulinaemic conditions. Whole body glucose uptake, as determined by the euglycaemic clamp technique, was significantly lower in the patients with NIDDM (35+/-3 micromol/kg body weight min) than the normal subjects (45+/-3 micromol/kg body weight x min, p < 0.02). Insulin-stimulated femoral muscle glucose uptake was significantly lower in the patients with NIDDM (71+/-6 micromol/kg muscle x min) than in the normal subjects (96+/-5 micromol/kg muscle x min, p < 0.01). Whole body glucose uptake was correlated with femoral muscle glucose uptake in the entire group (r=0.76, p < 0.001), in patients with NIDDM and in normal subjects. Rates of insulin-stimulated myocardial glucose uptake were comparable between the patients with NIDDM (814+/-76 micromol/kg muscle min) and the normal subjects (731+/-63 micromol/kg muscle min, p > 0.4). Whole body or femoral muscle, and myocardial glucose uptake were not correlated in all subjects, patients with NIDDM or normal subjects. We conclude that insulin resistance of the myocardium is not a feature of uncomplicated NIDDM.

Blood Glucose↗
PubMed1998

Components of the insulin resistance syndrome are associated with progression of atherosclerosis in non-grafted arteries 5 years after coronary artery bypass surgery.

AIMS: Risk factors for progression of atherosclerosis in non-grafted coronary arteries were examined in a prospective 5-year follow-up study of 228 consecutive coronary artery bypass surgery patients, with the main emphasis on insulin resistance syndrome. METHODS AND RESULTS: Serum lipids and lipoproteins were measured pre-operatively and 1, 2, 3 and 5 years after surgery; and a baseline oral glucose tolerance test with plasma insulin determinations was performed pre-operatively. Progression of atherosclerosis was assessed by means of computer-based quantitative coronary angiography. Compared to subjects without progression, the patients with progression of atherosclerotic lesions had a higher body mass index both at baseline (P = 0.022) and at 5 years (P = 0.007), were more often treated for hypertension at baseline (P = 0.008) and at 5 years (P = 0.012), used diuretics more often during the follow-up period (P = 0.002), had a larger blood glucose area under the curve (P = 0.015) and a lower insulin sensitivity index (P = 0.006) in the baseline oral glucose tolerance test, had a higher serum total cholesterol concentration at baseline (P = 0.044), and a higher serum triglyceride concentration (P = 0.005) during the whole follow-up period. Clustering of the components of insulin resistance syndrome at baseline was more frequently found in patients with progression of atherosclerotic lesions than in patients without progression (P = 0.025). For example, for patients with < or = 1 component, the risk of progression was 17%, while for patients with > or = 5 components the risk was 67%. As compared to the other patients, those with new atherosclerotic lesions had a lower insulin sensitivity index at baseline (P = 0.033), and a lower serum high density lipoprotein cholesterol concentration during the follow-up period (P = 0.033). CONCLUSION: In addition to high serum cholesterol, the components of the insulin resistance syndrome are associated with progression of atherosclerosis in non-grafted coronary arteries 5 years after coronary artery bypass surgery.

Adult↗
PubMed1998

Angiographic changes in saphenous vein grafts and atherosclerosis risk factors. A 5-year study with serial measurements of serum lipids and lipoproteins.

The association between cardiovascular risk factors and stenosis or occlusion of saphenous vein grafts was analysed in a prospective 5-year study of 176 unselected patients with coronary artery bypass grafting (CABG). Methods included serial measurements of serum lipids and lipoproteins, determination of apolipoprotein E phenotype, lipoprotein (a) levels 5 years postoperatively, and subcutaneous fat biopsy to determine the fatty acid composition before and one year after CABG. Graft angiography with quantitative analysis of angiograms was performed at the end of follow-up. A coronary artery with diameter < or = 1.5 mm was associated with occlusion of vein grafts (p < 0.01). The mean levels of serum lipids and lipoproteins, other traditional risk factors for atherosclerosis, and subcutaneous fatty acid composition were similar in patients with and without graft occlusion, and similar when the maximum diameter of non-occluded grafts was < 50% vs > or = 50%, and < 25% vs > or = 25%. High lipoprotein (a) concentration tended to be associated with obstructive changes in vein grafts. Our data indicate that, because lipids, lipoproteins and other traditional cardiovascular risk factors do not predict occlusion or stenosis of saphenous vein grafts five years after CABG, it is not currently possible to predict directly from the levels of these risk factors which patients are likely to benefit from pharmacological or other interventions.

Arteriosclerosis↗
PubMed1998

Serum uric acid is a strong predictor of stroke in patients with non-insulin-dependent diabetes mellitus.

BACKGROUND AND PURPOSE: Patients with non-insulin-dependent diabetes mellitus (NIDDM) are at increased risk for stroke. Hyperuricemia is a common finding in NIDDM, but its significance as an independent risk factor for cardiovascular disease has remained uncertain. Therefore, we investigated serum urate as a predictor of stroke in NIDDM patients free of clinical nephropathy (ie, with a serum creatinine level of < or = 120 micromol/L). METHODS: In this population-based study, cardiovascular risk factors were determined in 1017 patients (551 men and 466 women) with NIDDM, aged 45 to 64 years at baseline. The patients were followed up for 7 years with respect to stroke events. RESULTS: During the follow-up period, 31 NIDDM patients (12 men [2.2%] and 19 women [4.1%]) died from stroke and 114 NIDDM patients (55 men [10.0%] and 59 women [12.7%]) had a fatal or nonfatal stroke. The incidence of stroke increased significantly by quartiles of serum uric acid levels (P<.001). High uric acid level (above the median value of > 295 micromol/L) was significantly associated with the risk of fatal and nonfatal stroke by Cox regression analysis (hazard ratio, 1.93 [1.30 to 2.86]; P=.001). This association remained statistically significant even after adjustment for all cardiovascular risk factors (hazard ratio, 1.91 [1.24 to 2.94]; P=.003). CONCLUSIONS: Our results indicate that hyperuricemia is a strong predictor of stroke events in middle-aged patients with NIDDM independently of other cardiovascular risk factors.

Cerebrovascular Disorders↗
PubMed1998

Serum lipids, lipoproteins, and lipid metabolizing enzymes in identical twins discordant for obesity.

Obesity is associated with adverse changes in plasma lipoprotein metabolism, but it is not known completely how this association is modified by genetic factors. We assessed the contribution of obesity to serum lipid and lipoprotein levels and lipid metabolizing enzyme activities by examining 23 identical twin pairs (9 male, 14 female) who had, on the average, an 18-kg intrapair difference in BW. Compared with lean co-twins, obese co-twins had approximately 20% higher low-density lipoprotein (LDL) cholesterol (P < 0.01), 20% lower high-density lipoprotein2 cholesterol (P = 0.010), and 90% (men) or 35% (women) higher (P < or = 0.06) total, very-low-density lipoprotein and LDL triglycerides. The pairs were divided into subgroups by the gender-specific median value of abdominal visceral fat (AVF) area in the obese co-twin and by apolipoprotein E 4 phenotype. The intrapair differences in serum cholesterol fractions were similar in twin pairs with high or low AVF, whereas only high AVF pairs showed significant differences in triglyceride fractions. The greatest intrapair differences in total, very-low-density lipoprotein and LDL triglycerides were observed in apolipoprotein E 4-positive pairs expressing high AVF. Compared with lean co-twins, lecithin cholesterol acyltransferase activity was 18% higher (P < 0.001) and hepatic lipase activity was 38% higher (P = 0.016) in obese co-twins with high AVF. When genetic factors are identical, obesity is associated with an atherogenic lipid profile, especially in subjects with high visceral fat accumulation.

Apolipoprotein E4↗
PubMed1998

Coronary flow reserve is reduced in young men with IDDM.

Disturbances of coronary circulation have been reported in diabetic patients with microvascular complications but without obstructive coronary atherosclerosis. The aim of the present study was to investigate coronary flow reserve in young adult patients with IDDM but without microalbuminuria and diabetic autonomic neuropathy. Coronary flow reserve was determined in 12 nonsmoking male patients with IDDM (age 30.0 +/- 6.6 years) and 12 healthy matched volunteers. Groups were similar with respect to blood pressure and serum lipid concentrations, and no subject had a positive family history of coronary heart disease. The patients with IDDM had normal exercise echocardiography and autonomic nervous function tests. Five patients had minimal background retinopathy, and none had microalbuminuria. Positron emission tomography and [15O]H2O were used to measure myocardial blood flow at rest and after dipyridamole administration. The studies were performed during euglycemic hyperinsulinemia (serum insulin approximately 70 mU/l). The baseline myocardial blood flow was similar in patients with IDDM and in control subjects (0.84 +/- 0.18 vs. 0.88 +/- 0.25 ml x g(-1) x min(-1), NS). The myocardial blood flow during hyperemia was 29% lower in patients with IDDM (3.17 +/- 1.57) compared with the control subjects (4.45 +/- 1.37 ml x g(-1) x min(-1), P < 0.05). Consequently, coronary flow reserve (the ratio of flow during hyperemia and at rest) was lower in diabetic patients than in control subjects (3.76 +/- 1.69 vs. 5.31 +/- 1.86, P < 0.05) and the total coronary resistance during hyperemia was higher in diabetic patients (53.7 +/- 31.5) compared with the control subjects (31.4 +/- 11.6 mmHg x min x g x ml(-1), P < 0.05). The coronary flow reserve was similar in diabetic patients with and without mild background retinopathy. No association was found between the coronary flow reserve and serum lipid or HbA1c values in either group. Coronary flow reserve is impaired in young adult males with IDDM and no or minimal microvascular complications and without any evidence of coronary heart disease. This abnormality cannot be explained by standard coronary heart disease risk factors. The results imply early impairment of coronary vascular reactivity in IDDM patients, which may represent an early precursor of future coronary heart disease or may contribute to the pathogenesis of diabetic cardiomyopathy.

Adult↗