Toshikazu Yamanouchi

Plasma 1,5-Anhydro-D-Glucitol as New Clinical Marker of Glycemic Control in NIDDM Patients

To elucidate the value of using plasma 1,5-anhydro-D-glucitol (AG) as a marker of glycemic control in diabetic patients, the relationship between the plasma concentration of AG and glucosuria was examined in 152 patients with non-insulin-dependent diabetes mellitus (NIDDM). After recovery from the deterioration of glycemic control in NIDDM patients had started, AG began to increase day by day. The recovery of plasma AG showed a constant linear increase curve when excellent glycemic control was attained. The ordinary daily recovery rate of plasma AG was estimated to be 0.3 μg/ml, which was independent of body weight, sex, age, the difference in treatment, the duration of diabetes, or the level of plasma AG among NIDDM patients. This rate decreased according to the increase in urinary glucose. When we calculated the decrease rate of plasma AG (ΔAG), assuming 0.3 μ/day to be the maximum increase rate in a day, we found a high correlation between βAG and urinary glucose at almost all AG levels except the normal range and observed that plasma AG ((A)) times urinary glucose (G) was relatively constant. The formula A × G = 16 is a simple equation for rough estimation of urinary glucose from the plasma AG concentration in a stable glycemic-controlled NIDDM patient, and we call it the A ⋅ G index. The plasma AG also correlated significantly with fasting plasma glucose (r = −.810) and glycosylated hemoglobin (r = −.856) in the same stable glycemic-controlled NIDDM patients. Based on these observations, we propose that plasma AG can serve as a new marker that may provide sensitive and analytical information about glycemic control.

Rats Fed Fructose-Enriched Diets Have Characteristics of Nonalcoholic Hepatic Steatosis

Nonalcoholic steatohepatitis (NASH) and nonalcoholic fatty liver disease are increasing in adults and are likely to be increasing in children. Both conditions are hepatic manifestations of metabolic syndrome. Experimental animals fed fructose-enriched diets are widely recognized as good models for metabolic syndrome. However, few reports have described the hepatic pathology of these experimental animals. In this study, 5-wk-old Wistar specific pathogen-free rats, which are a normal strain, were fed experimental diets for 5 wk. We then evaluated the degree of steatohepatitis. The 5 diet groups were as follows: cornstarch (70% wt:wt) [control (C)], high-fructose (70%) (HFr), high-sucrose (70%) (HS), high-fat (15%) (HF), and high-fat (15%) high-fructose (50%) (HFHFr) diets. The macrovesicular steatosis grade, liver:body weight ratio, and hepatic triglyceride concentration were significantly higher in the HFr group than in the other 4 groups. However, the HFr group had a significantly lower ratio of epididymal white fat:body weight than the other 4 groups and had a lower final body weight than the HF and HFHFr groups. The HF group had a greater final body weight than the C, HFr, and HS groups, but no macrovesicular steatosis was observed. The HFr group had a significantly higher grade of lobular inflammation than the other 4 groups. The distribution of lobular inflammation was predominant over portal inflammation, which is consistent with human NASH. In conclusion, rats fed fructose-enriched diets are a better model for NASH than rats fed fat-enriched diets.

Serum 1,5-anhydroglucitol (1,5 AG): new clinical marker for glycemic control.

We review the use of 1,5-anhydroglucitol (1,5 AG) in diagnosing and monitoring patients with diabetes. This six-carbon chain monosaccharide is one of the major polyols present in humans. Its concentration in serum is normally about 12 to 40 micrograms/ml. This substance is derived mainly from food, is well absorbed in the intestine, and is distributed to all organs and tissues. It is metabolically stable, being excreted in the urine when its level exceeds the renal threshold. It is reabsorbed in the renal tubules, and is competitively inhibited by glucosuria, which leads to a reduction in its level in serum. The correlation between this reduction and the amount of glucose present in urine is so close that 1,5 AG can be used as a sensitive, day-to-day, real-time marker of glycemic control. It provides useful information on current glycemic control and is superior to both HbA1c and fructosamine in detecting near-normoglycemia.

Comparison of 1,5-Anhydroglucitol, HbA1c, and Fructosamine for Detection of Diabetes Mellitus

To evaluate the use of serum 1,5-anhydroglucitol (AG) levels in screening for diabetes mellitus, we compared the sensitivity and specificity of HbA1c, fructosamine (FA), and AG in 1620 randomly selected subjects in 11 institutions throughout Japan. Most individuals were receiving diet and/or drug therapy for diabetes. Subjects were separated into four groups based on World Health Organization criteria: nondiabetic control subjects, subjects with impaired glucose tolerance (IGT), patients with diabetes, and patients with other disorders without IGT. The overlap of AG values between each group was less than that of HbA1c or FA values. AG levels were significantly correlated with fasting plasma glucose (r = −0.627), HbA1c (r = −0.629), and FA (r = −0.590) levels. If we took 14 μg/ml as the normal lower limit, AG level was highly specific (93.1%), and a decreased AG level indicated diabetes mellitus (84.2% sensitivity). According to the selectivity index (sensitivity value times specificity value), AG determinations were superior to both HbA1c and FA measurements for diabetes screening. When combinations of these tests were used, only AG and HbA1c together were slightly better than AG alone. Thus, together with other advantages of AG, e.g., its wide variance with relatively fair glycemic control and the negligible influence of the sampling conditions, AG level has more potential than HbA1c or FA level as a screening criterion for diabetes.

Reduction and Recovery of Plasma 1,5-Anhydro-D-Glucitol Level in Diabetes Mellitus

The plasma concentration of 1,5-anhydro-D-glucitol (AG) was measured in 135 newly diagnosed patients who were referred for oral glucose tolerance tests. AG concentrations in the nondiabetic patients indicated that the mean value of normal AG concentration was 21.8 μg/ml (SD = 5.9 μg/ml, range 9.6–38.8 μg/ml). This distribution of AG concentration was significantly different from that in patients with impaired glucose tolerance (IGT) (13.3 ± 5.4 μg/ml) and definitely different from that in diabetic patients (2.1 ± 1 . 8 μg/ml). In a standard glucagon test, it was suggested that the decrease of plasma AG was affected not only by glycemic control of the patients but also by pancreatic cell secretory activity. The reduction of AG concentration was more marked in IDDM patients than in NIDDM patients. In longitudinal studies, AG concentration was shown to be sensitive to glycemic control. However, its recovery showed a tendency toward much delay after the improvement of fasting blood glucose or HbA, concentrations. On the other hand, AG concentration showed negligible diurnal change and no immediate change as a result of diet, oral glucose load, or acute shift of the insulin level in both normal and diabetic subjects.

Regulation of adipocytokine secretion and adipocyte hypertrophy by polymethoxyflavonoids, nobiletin and tangeretin

AIMS The polymethoxyflavonoids nobiletin and tangeretin possess several important biological properties such as neuroprotective, antimetastatic, anticancer, and anti-inflammatory properties. The present study was undertaken to examine whether nobiletin and tangeretin could modulate adipocytokine secretion and to evaluate the effects of these flavonoids on the hypertrophy of mature adipocytes. MAIN METHODS All experiments were performed on the murine preadipocyte cell line 3T3-L1. We studied the formation of intracellular lipid droplets in adipocytes and the apoptosis-inducing activity to evaluate the effects of polymethoxyflavonoids on adipocyte differentiation and hypertrophy, respectively. The secretion of adipocytokines was measured using ELISA. KEY FINDINGS We demonstrated that the combined treatment of differentiation reagents with nobiletin or tangeretin differentiated 3T3-L1 preadipocytes into adipocytes possessing less intracellular triglyceride as compared to vehicle-treated differentiated 3T3-L1 adipocytes. Both flavonoids increased the secretion of an insulin-sensitizing factor, adiponectin, but concomitantly decreased the secretion of an insulin-resistance factor, MCP-1, in 3T3-L1 adipocytes. Furthermore, nobiletin was found to decrease the secretion of resistin, which serves as an insulin-resistance factor. In mature 3T3-L1 adipocytes, nobiletin induced apoptosis; tangeretin, in contrast, did not induce apoptosis, but suppressed further triglyceride accumulation. SIGNIFICANCE Our results suggest that nobiletin and tangeretin are promising therapeutic candidates for the prevention and treatment of insulin resistance by modulating the adipocytokine secretion balance. We also demonstrated the different effects of nobiletin and tangeretin on mature adipocytes.

A pilot clinical trial of a new oral hypoglycemic agent, CS-045, in patients with non-insulin dependent diabetes mellitus

CS-045, (+/-)-5-[4-(6-hydroxy-2,5,7,8-tetramkethylchroman-2- ylmethoxy)benzyl]-2,4-thiazolidinedione, lowers plasma glucose in several animal models of non-insulin dependent diabetes mellitus (NIDDM) presumably by increasing insulin sensitivity. Little adverse effect was found in a phase 1 study on healthy male subjects. In order to test its efficacy in lowering plasma glucose in NIDDM in man, a pilot multi-center clinical trial of CS-045 was carried out in 146 patients with NIDDM whose glycemic control was inadequate (FPG greater than 140 mg/dl) on diet and/or other oral hypoglycemic agents. CS-045 was given orally in a daily dose of 200 mg or 400 mg for 12 weeks in addition to the previous treatment. The mean fasting plasma glucose (FPG) and fructosamine began to decrease within 2 weeks and the mean HbA1c within 8 weeks. After 12 weeks, the FPG fell from 192 +/- 41 to 155 +/- 45 mg/dl (P less than 0.01), fructosamine from 3.7 +/- 0.6 to 3.3 +/- 0.6 (P less than 0.01), and HbA1c from 8.9 +/- 1.5 to 8.1 +/- 1.5% (P less than 0.01). The drug was effective in 39% of patients in that FPG fell by more than 20% of the initial value. This rate of efficacy was the same when CS-045 was given alone or together with other oral hypoglycemic agents. The drug was more effective in a dosage of 400 mg than with 200 mg (the rate of efficacy 46% vs 25%) and more effective in obese patients than in lean patients (46% vs 25%).(ABSTRACT TRUNCATED AT 250 WORDS)

Patient health literacy and patient-physician information exchange during a visit.

BACKGROUND Health literacy (HL), the capacity of individuals to access, understand and use health information to make informed and appropriate health-related decisions, is recognized as an important concept in patient education and disease management. OBJECTIVE To examine the relation of three levels of HL (i.e. functional, communicative and critical HL) to patient-physician information exchange during a visit. METHODS Participants were 134 outpatients with type 2 diabetes who were under continuous care by four attending physicians at a university-affiliated hospital. The visit communication was recorded and analysed using the Roter Interaction Analysis System. Patient HL was measured through a self-reported questionnaire using newly developed self-rated scales of functional, communicative and critical HL. Sociodemographic and clinical characteristics and patients perception of the information exchange were assessed for each patient through self-reported questionnaires and review of electronic medical records. RESULTS Patient HL levels were related to the information exchange process during the visit. Among the three HL scales, communicative HL (the capacity to extract information, derive meaning from different forms of communication and apply new information to changing circumstances) was related to patients perceptions of the information exchange. Further, patient communicative HL had a modifying effect on the relationship between physicians information giving and patients perception of it, suggesting that physicians communication may be perceived differently depending on the patients HL. CONCLUSION The exploration of patient HL may provide a better understanding of potential barriers to patient-physician communication and patients self-management of disease.

Estimation of plasma glucose fluctuation with a combination test of hemoglobin A1c and 1,5-anhydroglucitol☆

We investigated the effect of plasma glucose fluctuation on hemoglobin A1c (HbA1c) and plasma 1,5-anhydroglucitol (AG) levels, especially in insulin-dependent diabetes mellitus (IDDM). Plasma AG is a new marker that provides sensitive and analytical information on glycemic control. The basic mechanisms underlying both the reduction and recovery of the plasma AG level, ie, the excretion into urine with glucosuria and the amount supplied to the body, were presumed to be similar in IDDM and non-insulin-dependent diabetes mellitus (NIDDM) patients. The correlation coefficient for mean plasma glucose and AG was -.591, and it was .578 for mean plasma glucose and HbA1c in IDDM patients. In NIDDM, the correlation between mean plasma glucose and AG was -.869, and between mean plasma glucose and HbA1c, .875. The plasma AG levels in the IDDM group showed a lower range than in the NIDDM group, even with similar HbA1c levels. All the cases showing lower plasma AG levels among those with similar HbA1c levels manifested greater fluctuation of plasma glucose and a larger amount of urinary glucose. The lower AG level in IDDM patients was reversible to the level in NIDDM patients when the greater fluctuation of plasma glucose was corrected. Thus, it was suggested that because urinary glucose excretion is intermittently high in IDDM patients, plasma AG is frequently low, even though the mean plasma glucose and HbA1c levels suggest good control.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term sucrose-drinking causes increased body weight and glucose intolerance in normal male rats

The current epidemic of diabetes likely reflects marked changes in environmental factors, although genetic susceptibility plays a powerful role in the occurrence of diabetes in certain populations. We investigated whether long-term sucrose-drinking causes hyperglycaemia in male Wistar-Imamichi littermates (n 32), which are not genetically susceptible to diabetes or obesity. Each litter was divided equivalently into two groups, the sucrose group and the control group. The sucrose group received 300 g/l sucrose water and the control group received regular water until 42 weeks of age. Rats were weighed every 1 or 2 weeks. Oral glucose tolerance tests were performed at 28 and 36 weeks of age. Plasma glucose and insulin concentrations were measured. Body weights were significantly greater in the sucrose group than in the control group in 18-week-old rats (P<0.05), and the difference between the two groups reached 163 g by the end of the study (P<0.01). The 120 min post-load plasma glucose concentration in the sucrose group was 11.4 (SD 2.8) mmol/l in 28-week-old rats and 12.7 (SD 2.2) mmol/l in 36-week-old rats, while that of the control group remained approximately 7.3-7.7 mmol/l. In the sucrose group, the plasma insulin peak occurred 30 min post-load at 28 weeks of age; but the peak disappeared and hyperinsulinaemia was prolonged at 36 weeks of age. In conclusion, long-term sucrose-drinking causes increased body weight and glucose intolerance in normal male rats.