Genshi Egusa

Influence of obesity on the metabolism of apolipoprotein B in humans.

The influence of obesity on the metabolism of apolipoprotein B (apo B) in very low density lipoprotein (VLDL), intermediate density lipoprotein (IDL), and low density lipoprotein (LDL) was investigated in nine obese and seven nonobese Pima Indian men. Kinetics of VLDL-apo B (VLDL-B), VLDL-triglycerides, IDL-B and LDL-B were studied after injection of autologous 131I-VLDL, [3H]glycerol, and autologous 125I-LDL. Specific activities were measured in apo B isolated from all lipoprotein fractions and in triglyceride isolated from VLDL. Transport rates and fractional catabolic rates for apo B in VLDL, IDL, and LDL and triglyceride in VLDL were determined by multicompartmental analysis. This method also allowed the estimation of rates of interconversions of the lipoproteins. The two groups had similar mean ages and heights, but the obese group had a higher total body weight (131 +/- 14 vs. 66 +/- 3 kg +/- SEM) and fat free mass (81 +/- 5 vs. 54 +/- 2 kg) than lean controls. Plasma total lipids were similar for the two groups, and apo B concentrations in VLDL, IDL, and LDL were similar in obese and lean subjects. In spite of similarity in concentrations, obese subjects compared to lean subjects had higher synthetic rates of VLDL-triglyceride (62.6 +/- 15 vs. 26.2 +/- 7 g/d, P less than 0.01), VLDL-B (2,241 +/- 215 vs. 1,113 +/- 72 mg/d, P less than 0.001), and LDL-B (1,234 +/- 87 vs. 802 +/- 83 mg/d, P less than 0.01). Furthermore, in obese subjects, significantly higher amounts of VLDL-B were removed from the circulation without conversion to LDL-B (1,078 +/- 159 vs. 460 +/- 34 mg/d, P less than 0.05), and obese subjects had a higher fractional catabolic rate for LDL than the lean controls (0.48 +/- 0.02 vs. 0.41 +/- 0.02 d-1, P less than 0.05). The rapid catabolism of LDL and increased metabolism of VLDL without conversion to LDL in obese individuals may be mechanisms for maintenance of LDL at normal levels despite the overproduction of its precursor.

Coordination of very low-density lipoprotein triglyceride and apolipoprotein B metabolism in humans: Effects of obesity and non-insulin-dependent diabetes mellitus

To understand the relationship between very low-density lipoprotein (VLDL) triglyceride and VLDL apolipoprotein (apo) B, we studied their metabolisms simultaneously in 53 subjects with a range of obesity and glycemia. Obese subjects had increased production of both VLDL apo B and VLDL triglyceride and more VLDL of normal composition. Compared with nondiabetics, diabetic subjects had decreased clearance of both VLDL apo B and VLDL triglyceride, increased production of VLDL triglyceride but not of VLDL apo B, and more VLDL of abnormal composition. Production of both VLDL apo B and VLDL triglyceride were significantly correlated with plasma insulin concentrations, and rates of clearance of both were inversely correlated with plasma glucose. There was no direct correlation between total plasma free fatty acid concentration and production of either VLDL triglyceride or VLDL apo B, but VLDL triglyceride production was found to account for only a very small proportion of the nonoxidative component of free fatty acid turnover. We suggest that in obese subjects hyperinsulinemia induces overproduction of both VLDL apo B and VLDL triglyceride. In diabetes VLDL is increased in part because of decreased clearance; the altered composition is the result of the increase in VLDL-triglyceride production independent of apo B. The increase in VLDL triglyceride production may be mediated through plasma free fatty acids or glucose, although assessment of the relationship between these precursors and VLDL triglyceride is confounded by the fact that only a small portion of free fatty acids or glucose is converted to VLDL triglyceride.

Japan Atherosclerosis Society (JAS) Guidelines for Prevention of Atherosclerotic Cardiovascular Diseases 2017

Toray Industries, Inc., Tokyo, Japan Department of Diabetes, Metabolism and Endocrinology, Chiba University Graduate School of Medicine, Chiba, Japan National Center for Geriatrics and Gerontology, Aichi, Japan Department of Internal Medicine and Cardiology, Gifu Prefectural General Medical Center, Gifu, Japan Division of Diabetes and Metabolism, Department of Internal Medicine, Iwate Medical University, Iwate, Japan Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi, Japan Center for Integrated Medical Research, Hiroshima University Hospital, Hiroshima, Japan Egusa Genshi Clinic, Hiroshima, Japan Department of Cardiovascular Medicine, Juntendo University, Tokyo, Japan Preventive Medicine and Public Health, Keio University School of Medicine, Tokyo, Japan Biomedical Informatics, Osaka University, Osaka, Japan Division of Cardiology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan Department of Community Health Systems Nursing, Ehime University Graduate School of Medicine, Ehime, Japan Department of Vascular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan Department of Vascular Surgery, Saitama Medical Center, Saitama, Japan Chief Health Management Department, Mitsui Chemicals Inc., Tokyo, Japan Department of Pediatrics, Showa University School of Medicine, Tokyo, Japan Department of Neurology, Kita-Harima Medical Center, Hyogo, Japan Department of Internal Medicine, Mizonokuchi Hospital, Teikyo University School of Medicine, Kanagawa, Japan Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan Tsukasa Health Care Hospital, Kagoshima, Japan Faculty of Nutrition, Division of Clinical Nutrition, Kobe Gakuin University, Hyogo, Japan Department of Food and Nutrition, Faculty of Human Sciences and Design, Japan Women’s University, Tokyo, Japan 25 Department of Preventive Cardiology, National Cerebral and Cardiovascular Center, Osaka, Japan Department of Medical Statistics, Toho University, Tokyo, Japan Department of Clinical Innovative Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan Department of Laboratory Medicine, Jikei University Kashiwa Hospital, Chiba, Japan Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, Osaka, Japan Department of Obstetrics and Gynecology, Aichi Medical University, Aichi, Japan 31 Department of Community Medicine, Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Osaka, Japan Rinku General Medical Center, Osaka, Japan

Carotid Atherosclerosis and Serum Lipoprotein(a) Concentrations in Patients With NIDDM

OBJECTIVE To investigate the association of carotid atherosclerosis and serum lipoprotein(a) [Lp(a)] concentrations in subjects with NIDDM. RESEARCH DESIGN AND METHODS We measured carotid intima-media thickness (IMT) and Lp(a) concentrations in 117 NIDDM subjects. Subjects were divided into tertiles according to IMT values and number of plaques. RESULTS Serum Lp(a), but not lipid and apoprotein levels, increased significantly with increasing IMT (20.0 ± 2.3, 24.7 ± 3.3, and 39.8 ± 4.3 mg/dl [mean ± SE], respectively, P < 0.001). Serum Lp(a) increased with increasing number of plaques (18.4 ± 2.5 mg/dl in 59 subjects with no plaques, 25.8 ± 2.5 mg/dl in 24 subjects with 1 plaque, and 38.7 ± 5.1 mg/dl in 34 subjects with more than 1 plaque; P < 0.05). Furthermore, the mean IMT and Lp(a) levels in the subjects with cerebrovascular disease (CD) were significantly higher than in those without CD (1.25 ± 0.04 mm and 41.2 ± 4.7 mg/dl vs. 1.08 ± 0.03 mm and 22.2 ± 1.9 mg/dl; P < 0.005). The mean IMT and Lp(a) levels were higher in subjects with ischemic heart disease (IHD) than in those without IHD, although statistical significance was not observed (1.21 ± 0.06 mm and 31.7 ± 4.7 mg/dl vs. 1.10 ± 0.03 mm and 27.0 ± 2.4 mg/dl, respectively). CONCLUSIONS Elevated serum Lp(a) concentrations are associated with carotid atherosclerosis in NIDDM subjects.

Dissociation of Microangiopathy and Macroangiopathy in Patients With Type 2 Diabetes

OBJECTIVE Although persistent hyperglycemia contributes greatly to the progression of diabetic micro- and macroangiopathy, microangiopathy progresses more rapidly than macroangiopathy in some type 2 diabetic patients, with the opposite being true in others. This study was conducted to identify factors responsible for such dissociation. RESEARCH DESIGN AND METHODS Patients with proliferative diabetic retinopathy and a carotid intima-media thickness (IMT) level ≤1.0 mm were classified as the microangiopathy group (MIG); those with an IMT level >1.1 mm and without retinopathy or with background retinopathy were assigned to the macroangiopathy group (MAG). Only middle-aged patients, 50–69 years old, were included in this study. There were 54 patients in the MIG and 68 patients in the MAG. RESULTS Patients in the MIG were significantly younger at the onset of diabetes, and those in the MAG had a significantly higher mean ratio of apoprotein (apo) B to apoAI. The percentage of patients with a family history of diabetes was significantly higher in the MIG. Maternal inheritance was common among these patients. Those with obesity, a family history of diabetes, and younger onset of hypertension were more common in the MAG. In the multiple logistic regression analyses, maternal inheritance and early onset of diabetes were independent risk factors for the acceleration of microangiopathy. A personal history of obesity and a family history of hypertension were independently related to the development of macroangiopathy. CONCLUSIONS Our results suggest that patients with early onset and maternal inheritance of diabetes may have a high risk for the progression of diabetic microangiopathy, while patients with hyperlipidemia, a history of obesity, and a family history of hypertension seem prone to the development of atherosclerosis.

Hyperlipemia and Arteriosclerotic Cardiovascular Disease in the Polynesian Population of Rarotonga

Total cholesterol, total triglyceride and high density lipoprotein (HDL) cholesterol and their relation to arteriosclerotic cardiovascular disease (ASCVD) were investigated in a population of Polynesian Maoris in Rarotonga who are becoming increasingly westernized. 8.5% of the population had plasma triglyceride elevations (triglyceride greater than or equal to 200 mg/dl), and the occurrence of hypertriglyceridemia was significantly higher in males than females. 5.8% of the population had elevations of total cholesterol (cholesterol greater than or equal to 250 mg/dl), and the proportion with elevation of total cholesterol was similar for males and females. 3.2% of the population had elevations of both triglyceride and cholesterol. HDL cholesterol concentrations were relatively low, and no sex differences were observed at any age. Analysis of lipoprotein cholesterol and triglyceride in a subset of those who had hyperlipemia indicated that the elevations of total cholesterol and triglyceride were mainly due to elevations of low density lipoprotein (LDL) cholesterol and very low density lipoprotein (VLDL) triglyceride, respectively; furthermore, elevations of VLDL triglyceride and LDL cholesterol were significantly correlated with increase in VLDL apolipoprotein B (apo B) and LDL apo B, respectively. Although an appreciable prevalence of diabetes was observed in this population (male: 6.7%, female: 8.4%), the diabetes could not account for the hyperlipemia. Among 693 subjects between the ages of 30 and 59 years, approx. 3% of males and 1% of females had Q-wave changes, and 16% of females and 4% of males had ST-T changes. Among males with Q-wave abnormalities, hyperlipemia was more frequent. There was also increased frequency of hypertension in those with elevated lipids. The data indicate the occurrence of some hyperlipemia in this population which could be of the familial-combined type; the elevated plasma lipids may contribute to the increased frequency of coronary heart disease.

Serum and Urinary Type IV Collagen Concentrations in the Assessment of Diabetic Microangiopathy

We investigated the role of measurement of serum and urinary type IV collagen (IV-C) levels in monitoring diabetic microangiopathy. Furthermore, we compared these levels in diabetic nephropathy and non-diabetic renal disease (NDRD). A one-step sandwich enzyme immunoassay was used to measure IV-C levels in 82 diabetic patients, 33 NDRD patients and 20 healthy non-diabetic control subjects. The diabetic patients were classified into four groups according to urinary albumin/creatinine index (ACI) (mg/g) and serum creatinine (s-Cr) (mg/dl): normoalbuminuria (ACI < 30), microalbuminuria (ACI 30-300), albuminuria (ACI > 300, s-Cr < 1.99 mg/dl) and renal insufficiency (s-Cr > 1.99 mg/dl). Serum and urinary IV-C levels were significantly elevated even in diabetic patients without clinical evidence of microangiopathy compared with control subjects (p < 0.05 and p < 0.01, respectively). Both levels were significantly higher in normoalbuminuric patients than in the control subjects, and in patients with microalbuminuria, albuminuria or renal insufficiency than in normoalbuminuric patients, with significant differences between these groups (serum and urinary IV-C, both p < 0.0001 by ANOVA). Urinary IV-C and albumin levels were significantly correlated, even in normo- and microalbuminuric patients (r = 0.55, p < 0.0001). Serum IV-C in normoalbuminuric patients rose significantly as the degree of retinopathy progressed from background to proliferative stages (p < 0.05). Neither serum nor urinary IV-C levels were influenced by glycemic control. Albuminuric diabetic patients (with and without renal insufficiency) had significantly higher levels of serum IV-C compared with those in proteinuric NDRD patients (p < 0.005), though there was no significant difference in the urinary IV-C level. However, the urinary IV-C/albumin ratio was significantly higher in albuminuric diabetic patients than in proteinuric NDRD patients, even after adjusting for s-Cr and creatinine clearance (p < 0.0001). In conclusion, we suggest that measured serum and urinary IV-C concentrations may serve as new markers for monitoring the development and progression of diabetic microangiopathy, particularly nephropathy. Furthermore, the measurement of serum IV-C concentrations and urinary IV-C/albumin ratios in diabetic patients may allow diabetic nephropathy and non-diabetic renal disease to be differentiated.

Progression of Carotid Atherosclerosis in Two Japanese Populations with Different Lifestyles

Aim: We have conducted medical surveys on two Japanese populations (Japanese Americans living in the US and native Japanese living in Japan) to investigate the impact of westernization of lifestyles on diseases in Japanese people. A 1998 survey revealed that the progression of carotid intima-media wall thickness (IMT) was faster by approximately 20 years in Japanese Americans than in native Japanese. In this study, we compared the progression of atherosclerosis in native Japanese versus that in Japanese Americans using carotid IMT data from medical examinations conducted in the 2010s. Methods: This study included 115 native Japanese living in Hiroshima who underwent a medical examination in 2014 and 112 Japanese Americans living in Hawaii who underwent a medical examination in 2012, excluding those receiving medication for diabetes mellitus (DM) or dyslipidemia. Carotid IMT was compared between the two Japanese populations. Results: Serum total and low-density lipoprotein cholesterol levels were significantly higher in native Japanese than in Japanese Americans. The median carotid IMT was significantly greater in Japanese Americans than in native Japanese [median (25th–75th percentile): 1.27 (0.86–2.02) mm vs. 1.00 (0.80–1.30) mm, P = 0.001]. Regression curves showed that the age at which IMT exceeded 1.1 mm was estimated at > 50 years in Japanese Americans and at approximately 60 years in native Japanese. Conclusions: According to surveys conducted in 2012 and 2014, carotid IMT was still greater in Japanese Americans than in native Japanese. However, a comparison with data from the 1998 survey showed that current native Japanese had higher serum lipid levels and more advanced atherosclerosis.