Inactive aldehyde dehydrogenase 2 worsens glycemic control in patients with type 2 diabetes mellitus who drink low to moderate amounts of alcohol

BACKGROUND

Alcohol intake can have hypoglycemic or hyperglycemic effects in patients with type 2 diabetes mellitus. The present study was designed to investigate the glycemic control of male patients with diabetes mellitus from the aspect of the genetic status of alcohol metabolism.

METHODS

One hundred sixty-three men with type 2 diabetes mellitus were enrolled in the present study. They were all outpatients at the Diabetes Center of Saiseikai Central Hospital. The genotype of the aldehyde dehydrogenase 2 (ALDH2) gene of each patient was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and the patients were divided into those with active or inactive ALDH2 phenotype. We compared the amount of habitual alcohol intake and clinical data that included physical findings and blood chemistry of the patients in the active and inactive ALDH2 groups. The glycemic control of each patient was evaluated by the serum level of HbAlc.

RESULTS

Of the 163 patients with type 2 diabetes mellitus, 90 patients had the active ALDH2 phenotype and 73 patients had the inactive ALDH2 phenotype. The mean HbA1c level of the active ALDH2 group was nearly the same as that of the inactive ALDH2 group. However, the HbA1c level of the light-to-moderate drinkers (1-400 g/week) in the inactive ALDH2 group was highest and was significantly higher than the HbA1c level of the light-to-moderate drinkers of the active ALDH2 group. The HbA1c of the patients with diabetic complications was higher than the HbAlc of those without diabetic complications in both the active and inactive ALDH2 groups. However, the HbA1c level of the light-to-moderate drinkers without diabetic complications in the inactive ALDH2 group was significantly higher and the incidence of 24 hr urinary C-peptide was higher than the respective level of the light-to-moderate drinkers without diabetic complications in the active ALDH2 group.

CONCLUSIONS

Habitual light-to-moderate alcohol intake worsens glycemic control in diabetic patients who have the inactive ALDH2 phenotype. The data on 24 hr urinary C-peptide level suggested that increased acetaldehyde after light-to-moderate drinking by inactive ALDH2 diabetic patients may increase the HbA1c value by the insulin-resistant condition that resulted in hyperinsulinemia.

Effects of different types of injury to the inferior alveolar nerve on the behavior of Schwann cells during the regeneration of periodontal nerve fibers of rat incisor

The present study reports on different regeneration patterns of axons and Schwann cells in the periodontal ligament of the rat incisor using immunohistochemistry of protein gene product 9.5 (PGP 9.5) and S-100 protein. Three kinds of injury (transection, crush and segmental resection) were applied to the inferior alveolar nerve. In normal animals, PGP 9.5- and S-100-immunoreactivities were detected in the axons and Schwann cell elements of periodontal Ruffini endings, respectively. They were restricted to the alveolus-related part, occurring only rarely in the tooth-related part and in the shear zone (the border between the alveolus-related and tooth-related parts). Both transection and segmental resection caused the complete disappearance of PGP 9.5-immunoreactive nerve fibers in the periodontal ligament, while a small number of them could be found following the crush injury. Regenerating PGP 9.5-reactive nerve fibers appeared at 5 days and 21 days following the transection and segmental resection, respectively. The regeneration of periodontal nerve fibers completed in a period of 21-28 days and 14-21 days following the transection and crush, respectively, but was not completed even at 56 days following the segmental resection. The behavior of Schwann cells during regeneration was similar after the different nerve injuries; spindle-shaped S-100-immunoreactive cells, presumably Schwann cells, appeared in the shear zone and the tooth-related part. These cells disappeared 5-7 days prior to the completion of the regeneration of axonal elements of the periodontal ligament following the transection and crush. Following the segmental resection, in contrast, spindle-shaped S-100-positive cells disappeared from the tooth-related part at 42 days, although the axonal regeneration of periodontal Ruffini endings proceeded even until 56 days. We thus conclude that the duration of the migration of Schwann cells depends on the state of the regeneration of axons.

Immunohistochemical detection of heme oxygenase-2 in the periodontal Ruffini ending of the rat incisor

The present study was carried out to examine the occurrence of heme oxygenase-2 (HO-2) in the periodontal ligament of the rat incisor. HO-2-like immunoreactive (-IR) structures showed dendritic profiles, resembling the Ruffini endings, in the alveolar half of the ligament of rat incisor. Neither thin nerve fibers nor perivascular nerve fibers displayed HO-2-like immunoreactivity (-LI). No non-neural elements exhibited HO-2-LI. Electron microscopy revealed that immunoreactions were diffusely observed in the axon terminals of the Ruffini endings, but neither terminal Schwann cells nor Schwann sheaths contained immunoreactions for HO-2. Both most neurons in the trigeminal ganglion and trigeminal mesencephalic nucleus showed HO-2-LI. The presence of HO-2 in the periodontal Ruffini endings and its absence in the periodontal thin nerve fibers suggest the involvement of carbon monoxide produced by HO-2 in mechanoreception in the periodontal ligament.

Activation of the visual cortex imaged by 24-channel near-infrared spectroscopy

Near-infrared spectroscopy (NIRS) is a noninvasive technique for continuous monitoring of the amounts of total hemoglobin (total-Hb), oxygenated hemoglobin, (oxy-Hb) and deoxygenated hemoglobin (deoxy-Hb). The purpose of the present study was to demonstrate the utility of NIRS in functional imaging of the human visual cortex. A new NIRS imaging system enabled measurements from 24 scalp locations covering a 9 cm sq area. Topographic images were obtained from interpolations of the concentration changes between measurement points. Five healthy subjects between 25 and 49 years of age were investigated. After a resting baseline period of 50 s, the subjects were exposed to a visual stimulus for 20 s, followed by a 50 s resting period in a dimly lit, sound attenuating room. The visual stimulus was a circular, black and white, alternating checkerboard. In four of five subjects the visual cortex was the most activated area during visual stimulation. This is the first reported use of a NIRS-imaging system for assessing hemodynamic changes in the human visual cortex. The typical hemodynamic changes expected were observed; the total-Hb and oxy-Hb increased just after the start of stimulation and plateaued after 10 s of the stimulation period.

Altered distribution of Schwann cells in the periodontal ligament of the rat incisor following resection of the inferior alveolar nerve: an immunohistochemical study on S-100 proteins

The present study employed immunohistochemistry for the detection of S-100 proteins to reveal the alteration in the distribution of Schwann cells in the periodontal ligament of the rat incisor following resection of the inferior alveolar nerve (IAN). In normal animals, S-100-immunostaining demonstrated the profiles of Ruffini endings, primary mechanoreceptors in the periodontal ligament, in the alveolus-related part of the ligament. Under the electron microscope, S-100-like immunoreactivity (-LI) was observed in the cytoplasm of the terminal Schwann cell elements and in some axon profiles of the Ruffini endings. During the regeneration, S-100-like immunoreactive (-IR) terminal Schwann cells in the alveolus-related part of the ligament gradually decreased in number. In contrast, S-100-LI was found in the spindle-shaped cells at the shear zone (the border between alveolus-related and tooth-related parts) and in the tooth-related part, where S-100-LI was rarely detected in normal animals. Immunoelectron microscopic observations revealed that some S-100-IR spindle-shaped cells contained fibrous long spacing (FLS) fibers, suggesting that they were Schwann cells. Some regenerating axons were observed at the shear zone, but were rarely found in the tooth-related part. With the progress of the regeneration of the periodontal Ruffini endings, S-100-IR terminal Schwann cells became rearranged in the alveolus-related part by 42-56 days post injury, whereas the S-100-IR spindle-shaped Schwann cells in the shear zone and tooth-related part disappeared when the regeneration was complete.

Heterogeneous localizations of Trk B among individual periodontal Ruffini endings in the rat incisor

The present immunocytochemical study examined the localization of Trk B, a high affinity neurotrophin receptor, in the neural elements of the periodontal ligament of the rat incisor. In light microscopy, the immunoreactivity was demonstrated in dendritic profiles in the alveolar half of the periodontal ligament. Their location and morphological features indicated that they were periodontal Ruffini endings. Occasional rounded cells associated with periodontal Ruffini endings, which had immunonegative kidney-shaped nuclei, were immunoreactive; these were judged to be terminal Schwann cells. Immunoelectron microscopy revealed the heterogeneous localization of Trk B among individual Ruffini endings. Some terminal Schwann cells contained immunoreactive products for Trk B in the cytoplasm, while others did not. Similarly, a part of the Schwann sheaths covering the axon terminals showed Trk B immunoreactivity. Most axon terminals associated with periodontal Ruffini endings were immunopositive for Trk B, though a few of them were immunonegative. The ordinary Schwann cells did not contain Trk B immunoreactive products. These findings imply that Trk B is required for the maintenance of periodontal Ruffini endings. The different expression pattern of Trk B suggests that neuronal and glial elements comprising individual periodontal Ruffini endings are subject to heterogeneous conditions with regard to the requirement of Trk B.

[Relationship between diabetes mellitus-associated obstructive sleep apnea syndrome and hyperinsulinemia]

The purpose of this study was to examine the prevalence of sleep disordered breathing and background factors, especially hyperinsulinemia, in diabetic patients. The subjects were 70 patients randomly selected from 143 noninsulin-dependent diabetic patients hospitalized for educational purposes. Obstructive sleep apnea syndrome (OSAS) was diagnosed in 13 subjects, equivalent to a prevalence of 18.6%. The mean +/- S.D. immunoreactive insulin (IRI) values for 11 of the 13 OSAS patients (excluding insulin-treated patients) and for 49 non-OSAS patients were 10.7 +/- 6.8 microU/ml and 5.8 +/- 3.5 microU/ml, respectively. The value for the OSAS group was higher than that for the non-OSAS group (p = 0.04). However, a positive correlation between body mass index (BMI) and IRI was observed in both the OSAS (Y = 1.148 X - 20.006, r = 0.834, p = 0.001) and non-OSAS (Y = 0.466 X - 5.820, r = 0.524, p = 0.0001) groups. Multivariate analysis demonstrated that the presence of OSAS had a statistically significant influence on IRI (p = 0.001), but not on BMI (p = 0.391). These findings suggest that hyperinsulinemia may be exacerbated in diabetic patients with OSAS regardless of BMI.

A comparison of period amplitude analysis and FFT power spectral analysis of all-night human sleep EEG

Zero-cross and zero-derivative period amplitude analysis (PAA) data were compared with power spectral analysis (PSA) data obtained with the fast Fourier transform in all-night sleep EEG from 10 subjects. Although PAA zero-cross-integrated amplitude showed good agreement with PSA power in 0.3-2 Hz, zero-cross analysis appears relatively ineffective in measuring 2-4 Hz and above waves. However, PAA zero-derivative measures of peak-trough amplitude correlated well with PSA power in 2-4 Hz. Thus, while PAA appears able to measure the entire EEG spectrum, the analytic technique should be changed from zero cross to zero derivative at about 2 Hz in human sleep EEG. PAA and PSA both demonstrate robust and interrelated across-night oscillations in three frequency bands: delta (0.3-4 Hz); sigma (12-16 Hz); and fast beta (20-10 Hz). The frequencies between delta and sigma, and between sigma and fast beta, did not show clear across-night oscillations using either method, and the two methods showed lower epoch-to-epoch agreement in these intermediate bands. The causes of this reduced agreement are not immediately clear, nor is it obvious which method gives more valid results. We believe that the three strongly oscillating frequency bands represent fundamental properties of the human sleep EEG that provide important clues to underlying physiological mechanisms. These mechanisms are more likely to be understood if their dynamic properties are preserved and measured naturalistically rather than being forced into arbitrary sleep stages or procrustean models. Both PAA and PSA can be employed for such naturalistic studies. PSA has the advantages of applying the same analytic method across the EEG spectrum and rests on more fully developed theory. Combined zero-cross and zero-derivative PAA demonstrates EEG oscillations that closely parallel those observed with spectral power, and the PAA measures do not rely on assumptions about the spectral composition of the signal. In addition, both PAA techniques can measure the relative contributions of wave amplitude and incidence to total power: These waveform characteristics represent different biological processes and respond differentially to a wide range of experimental conditions.

Maternally transmitted susceptibility to non-insulin-dependent diabetes mellitus and left ventricular hypertrophy

OBJECTIVES

We studied the association of diabetes transmission with left ventricular hypertrophy (LVH) in patients with non-insulin-dependent diabetes mellitus (NIDDM).

BACKGROUND

It is suggested that NIDDM has a strong genetic basis and that maternally transmitted NIDDM is associated with mitochondrial deoxyribonucleic acid (DNA) mutations. However, genetic factors for LVH in NIDDM are unknown.

METHODS

We investigated the family history of diabetes and the prevalence of LVH using electrocardiography in 834 patients with NIDDM, of whom 199 also underwent echocardiography.

RESULTS

Of the 834 patients, 121 had diabetic mothers, 122 had diabetic fathers and 30 had both. The LVH criterion of S(v1) + R(V5) or R(v6) >35 mm was met in 148 patients. The percentage of patients having diabetic mothers was higher in those with LVH criterion (29%) than without it (16%) (p < 0.001), but the percentage of patients having diabetic fathers was similar in those with LVH (18%) and without it (18%). Compared with the 683 patients with nondiabetic mothers, the 151 patients with diabetic mothers were younger and had earlier onset of diabetes. The percentage of patients having diabetic siblings was also higher in those with diabetic mothers (31%) than in those with nondiabetic mothers (18%) (p < 0.001). On electrocardiograms, the prevalence of LVH was higher in patients with diabetic mothers (28%) than in those with nondiabetic mothers (15%) (p < 0.001). Echocardiograms showed that patients with diabetic mothers had greater left ventricular wall thickness and mass than those with nondiabetic mothers. In multivariate analysis, the family history of diabetes in mothers was an independent factor to LVH, but the family history of diabetes in fathers was not.

CONCLUSIONS

Maternal transmission of diabetes was associated with LVH in patients with NIDDM. Some genetic factors of diabetes, such as mitochondrial DNA abnormalities, may contribute to the development of LVH in maternally transmitted NIDDM.

T-cell insulitis found in anti-GAD65+ diabetes with residual beta-cell function. A case report

CASE HISTORY

We recently encountered a 65-year-old anti-GAD+ diabetic woman with residual beta-cell function who was proved to have T-cell insulitis. The proportion of CD4+ and CD8+ cells varied among individual islets, although CD4+ cells tended to be the predominant T-cell type in the islets examined. All of the islets examined still contained insulin, suggesting that beta-cell mass may have been preserved.

DISCUSSION

It is well known that lymphocytic infiltration of pancreatic islets, a condition referred to as "insulitis," is seen in acute-onset type 1 diabetes at autopsy and in biopsy specimens. However, there have been no proven cases of insulitis in type 1 diabetes with residual beta-cell function. We believe that this is the first type 1 diabetic patient with residual beta-cell function who was proven to have T-cell insulitis. This novel evidence will contribute to the proper classification and treatment of diabetes and to a better understanding of the pathophysiology of type 1 diabetes.

Immunohistochemical localization of S-100beta in the dental pulp of the rat molar

The present study was undertaken to reveal whether S-100alpha or S-100beta or both are present in the nerve fibers in the rat molar tooth pulp. No immunoreactivity for S-100alpha was observed in the molar pulp. In the root pulp, thick smooth-surfaced structures accompanying the blood vessel showed S-100beta-like immunoreactivity (-LI), and occasionally a very few thin beaded elements exhibited S-100beta-LI. In the coronal pulp, S-100beta-like immunoreactive (-IR) structures arborized repeatedly and extensively; they had a predominantly thick, smooth-surfaced appearance, though parts appeared thin and beaded. Numerous thin varicose S-100beta-IR structures ran through the odontoblast cell layer, and further penetrated into the predentin alongside the dentinal tubules. They could be traced for approximately 10-20 micrometers into the predentin from the pulp-predentin border. Immunoelectron microscopy revealed that the Schwann cells in the root pulp showed S-100beta-LI, and that S-100beta-LI was present in the axoplasm as well as Schwann cells in the coronal pulp. The S-100beta-IR axons were rarely surrounded by S-100beta-IR Schwann cells. In the predentin, S-100beta-IR nerve fibers terminated in a position close to the odontoblast processes. The present findings indicate that S-100beta, not S-100alpha, is present in the axon in the dental pulp and predentin as well as in the Schwann cells.

Rapid progression of cardiomyopathy in mitochondrial diabetes

Cardiac involvement and its clinical course in a diabetic patient with a mitochondrial tRNA(Leu)(UUR) mutation at position 3243 is reported in a 54-year-old man with no history of hypertension. At age 46, an electrocardiogram showed just T wave abnormalities. At age 49, it fulfilled SV1 + RV5 or 6>35 mm with strain pattern. At age 52, echocardiography revealed definite left ventricular (LV) hypertrophy, and abnormally increased mitochondria were shown in biopsied endomyocardial specimens. He was diagnosed as having developed hypertrophic cardiomyopathy associated with the mutation. However, at age 54, SV1 and RV5,6 voltages were decreased, and echocardiography showed diffuse decreased LV wall motion and LV dilatation. Because he had mitochondrial diabetes, the patient's heart rapidly developed hypertrophic cardiomyopathy, and then it seemed to be changing to a dilated LV with systolic dysfunction. Rapid progression of cardiomyopathy can occur in mitochondrial diabetes.

Immunocytochemical detection of S-100beta in the periodontal Ruffini endings in the rat incisor

Subcellular localization of S-100 protein, a kind of calcium binding proteins, was examined immunohistochemically in the Ruffini ending, a primary mechanoreceptor, in the periodontal ligament of the rat incisor. The periodontal ligament of the rat incisor was found to contain many S-100beta-immunoreactive (-IR) structures but no S-100alpha-IR elements. The S-100beta-IR structures ramified extensively to form Ruffini endings and were frequently associated with round cells, the terminal Schwann cells, which also showed S-100beta-like immunoreactivity. In many periodontal Ruffini endings, S-100beta-IR products were recognized in the cytoplasm of Schwann cells, but not in the axoplasm. However, some axon terminals which had fewer or shorter axonal fingers, were filled with S-100beta-IR products. The present findings indicated the existence of S-100beta, not S-100alpha, in axon terminals of the periodontal mechanoreceptive endings which were identified as type II Ruffini endings.

Usefulness of revised fasting plasma glucose criterion and characteristics of the insulin response to an oral glucose load in newly diagnosed Japanese diabetic subjects

OBJECTIVE

To examine the usefulness of the revised criterion for fasting plasma glucose (FPG) in the diagnosis of diabetes recommended by the American Diabetic Association (ADA) (126 mg/dl, 7 mmol/l), and to characterize insulin response during the 75-g oral glucose tolerance test (OGTT) in newly diagnosed Japanese diabetic subjects.

RESEARCH DESIGN AND METHODS

A series of 2,121 Japanese subjects underwent a 75-g OGTT (0-3 h) and were divided into three groups (normal glucose tolerance [NGT], impaired glucose tolerance [IGT], and diabetes mellitus [DM] according to the current World Health Organization criteria. After the cutoff values of FPG that distinguish NGT and IGT from diabetes were analyzed, the usefulness of the ADA criterion for FPG was examined by comparing diagnostic parameters (sensitivity, specificity, and accuracy) with those for the cutoff value of 140 mg/dl. To assess insulin response, both the insulinogenic index (IsIx), a marker of early secretion, and the area under the insulin response curve (AUCins), a marker of total secretion, were compared between the DM, NGT, and IGT groups.

RESULTS

First, the FPG cutoff value distinguishing NGT from diabetes was 109 mg/dl. An FPG of 126 mg/dl showed a higher sensitivity (0.52 vs. 0.31), the same specificity (1.00), and a higher accuracy (0.82 vs. 0.74) than an FPG of 140 mg/dl, and it had a higher specificity (1.00 vs. 0.86) with a slightly lower accuracy (0.82 vs. 0.85) than an FPG of 109 mg/dl. Second, the FPG cutoff value differentiating IGT from diabetes was 113 mg/dl. An FPG of 126 mg/dl showed a higher sensitivity (0.52 vs. 0.31) and accuracy (0.80 vs. 0.74) and a similar specificity (0.97 vs. 1.00) compared with an FPG of 140 mg/dl, and it had a higher specificity (0.97 vs. 0.82) with the same accuracy (0.80) as an FPG of 113 mg/dl. Third, the DM group showed the lowest IsIx among the three groups at all FPG values. The AUCIns in the DM group increased along with FPG, reached the maximum level at an FPG of 110 mg/dl, and declined thereafter. AUCIns was higher in the DM group than in the NGT group at FPG values > or = 100 mg/dl.

CONCLUSIONS

The revised ADA criterion for FPG of 126 mg/dl may improve diagnostic sensitivity without loss of specificity in Japanese diabetic subjects when compared with an FPG criterion of 140 mg/dl. Although early insulin secretion was impaired, total insulin secretion did not seem to be reduced in newly diagnosed Japanese diabetic subjects.

[Aldehyde dehydrogenase 2(ALDH2) gene polymorphism in NIDDM patients with chronic renal failure]

In order to investigate the influence of aldehyde dehydrogenase 2(ALDH2) genotype in the pathogenesis of nephropathy due to non-insulin dependent diabetes mellitus (NIDDM), genotyping of ALDH2 was measured using the PCR-RFLP method in patients with NIDDM on chronic hemodialysis (HD). The results were as follows; 1) The frequency of active ALDH2 was 63% and that of inactive ALDH2 was 37%. 2) The percentage of active ALDH2 was significantly higher in patients with alcohol tolerance than that in those without it (38%). 3) The estimated amount of alcohol consumption in the past was 506 +/- 720 g/week in the active ALDH2 group, and 156 +/- 288 g/week in the inactive ALDH2 group, showing a significant difference between the two groups. 4) Interdialytic body weight gain was larger in patients with active ALDH2 than in those with inactive ALDH2. Since the frequency of active ALDH2 was similar to that in patients without nephropathy, these results do not support the hypothesis that ALDH2 gene polymorphism is involved in the development and persistence of chronic renal failure due to NIDDM. However, salt and water craving in dialysis patients may be influenced partially by an active ALDH2 gene.

Malignant insulinoma with extensive liver metastases presenting as disturbance of consciousness

A 56-year-old man was referred to our hospital for evaluation of episodic disturbance of consciousness. Hypoglycemic symptoms were noted and Whipple's triad was satisfied. The 75 g OGTT and the glucagon test revealed a high baseline insulin level and hyperreactivity to glucagon. A pancreatic tumor and liver metastases were found by abdominal computed tomography (CT). Based on the finding of liver biopsy, the final diagnosis was malignant insulinoma with liver metastasis. He selected conservative treatment and no hypoglycemic crisis has occurred for one year since discharge. Early diagnosis and long-term follow-up is necessary since this tumor is slow growing.

Cerebral blood volume in the sleep measured by near-infrared spectroscopy

We investigated the relationship between hemodynamic changes in the cortex measured by near-infrared spectroscopy (NIRS) and the polysomnographic changes during sleep. Four healthy male volunteers participated in the study. Near-infrared spectroscopy measuring and polysomnographic recordings were done simultaneously during sleep. In many case, oxy-hemoglobin (oxy-Hb) decreased and deoxy-hemoglobin (deoxy-Hb) increased during the transition from wakefulness to sleep, and oxy-Hb increased toward deep sleep. Oxy-Hb and deoxy-Hb had larger fluctuations during REM sleep than those during non-REM sleep. During REM sleep, oxy-Hb often showed a lower level and deoxy-Hb showed a higher level than those during the preceding and following non-REM sleep.

The relationship between amniotic fluid macrophage colony-stimulating factor and fetal growth

The aim of this study was to clarify whether amniotic fluid macrophage colony-stimulating factor (M-CSF) is related to placental development and fetal growth. Maternal serum and amniotic fluid M-CSF levels were analyzed in 22 pregnant women (seven intrauterine growth retardation (IUGR) complicated and 15 normal pregnancies) at 33-40 weeks' gestation. Amniotic fluid was obtained by transabdominal amniocentesis performed under ultrasonographic guidance. The mean amniotic fluid M-CSF level of the IUGR-complicated pregnancy group (5.0 +/- 1.4 ng/ml) was significantly lower (P < 0.05) than that of the normal pregnancy group (7.4 +/- 1.6 ng/ml). All the IUGR-complicated pregnant women subsequently delivered small-for-gestational-age (SGA) infants with significantly lower placental weights than those of the normal infants. There was no significant correlation between amniotic fluid M-CSF levels and gestational age in the normal pregnancy group. The same scattergram showed the amniotic fluid M-CSF levels of the IUGR-complicated pregnancy group tended to be lower than those of the normal pregnancy group at 33-40 weeks' gestation. The results suggested that amniotic fluid M-CSF was one of the regulators of human placental development and was related to fetal growth.

Role of glycemic control and blood pressure in the development and progression of nephropathy in elderly Japanese NIDDM patients

OBJECTIVE

To investigate the role of glycemic control and blood pressure in the development and progression of nephropathy and to suggest goals for glycemic control and blood pressure for the prevention of nephropathy in elderly Japanese NIDDM patients.

RESEARCH DESIGN AND METHODS

A total of 123 age- and diabetes duration-matched elderly Japanese NIDDM patients (aged 60-75 years; 74 normoalbuminuric and 49 microalbuminuric) were retrospectively studied for 6 years.

RESULTS

The group that developed microalbuminuria from normoalbuminuria (group NM: n = 24) showed a higher 6-year mean HbA1c than the group that remained normoalbuminuric (group NN: n = 50; 9.0 +/- 0.8 vs. 8.1 +/- 0.8%, P < 0.01) in spite of no significant difference in 6-year mean blood pressure (MBP). On the other hand, the group that progressed from microalbuminuria to overt proteinuria (group MP: n = 26) showed a higher 6-year MBP than the group that remained microalbuminuric (group MM: n = 23; 106 +/- 5 vs. 95 +/- 6 mmHg, P < 0.01) in spite of no significant difference in 6-year mean HbA1c. The cutoff level of HbA1c separating group NN from group NM was 8.5% (normal range < or = 6.5%), and that of MBP separating group MM from group MP was 100 mmHg.

CONCLUSIONS

Glycemic control is a more potent factor than blood pressure level on the development of microalbuminuria. However, as far as the progression of microalbuminuria to overt proteinuria is concerned, hypertension is the most crucial factor in elderly NIDDM patients. Suggested goals for glycemic control and blood pressure level for the prevention of nephropathy in elderly Japanese patients are an HbA1c of < or = 8.5% (equivalent to 7.8% in the current measurement of stable HbA1c; normal range < or = 5.8%) and an MBP of < or = 100 mmHg.