Gastric inhibitory polypeptide responses and glucose turnover rates after natural meals in type II diabetic patients

Gastric inhibitory polypeptide (GIP) has insulinotropic actions in the presence of hyperglycemia. However, its extrapancreatic effects on glucose homeostasis are controversial. We have studied the relationships between GIP and immunoreactive insulin (IRI) and glucose turnover rates (D3H-3 glucose technique) in five poorly controlled type II diabetic patients and five normal subjects before and after a breakfast containing 500 kcal including 42 g sucrose. Mean fasting serum glucose levels and glucose responses were significantly (P less than 0.001) higher in the diabetic patients than in normal subjects. Mean basal serum IRI levels were similar in both groups [12.8 +/- 2.9 (SEM) vs. 11.8 +/- 2 microU/ml, P = NS]. After meal ingestion, mean IRI levels rose significantly to a peak at 20 min in the normal subjects but the responses were blunted in the diabetic patients (74 +/- 10 vs. 24 +/- 6 microU/ml, P less than 0.001). At all other times studied (60-180 min), mean serum IRI levels were similar in the diabetic patients and the normal subjects except at 180 min. Mean basal serum GIP levels were similar in the diabetic patients and the normal subjects (538 +/- 100 vs. 400 +/- 50 pg/ml, P = NS). After meal ingestion, mean GIP levels rose between 0-60 min but were significantly higher in the diabetic patients only at 20 min (1200 +/- 190 vs. 566 +/- 76 pg/ml, P less than 0.01). Mean basal hepatic glucose output was higher (P less than 0.01) in the diabetic patients. However, the mean basal MCR values were similar. After meal ingestion, total splanchnic glucose output and rates of glucose utilization (RU) were significantly higher in the diabetic patients compared with the normal subjects (P less than 0.001, and P less than 0.001, respectively). Postmeal MCR values were not statistically different in both groups. There were significant positive correlations between postmeal splanchnic glucose output and both IRI (r = 0.805, P less than 0.005) and GIP (r = 0.749, P less than 0.02) in the diabetic patients but not in the normal subjects (r = 0.10, P = NS for both). Whereas no relationships existed between RU and IRI in either group, RU correlated strongly with GIP (r = 0.810, P less than 0.005) only in the diabetic patients. We hypothesize that GIP may play a compensatory role to improve both impaired beta-cell insulin release and peripheral glucose utilization which are the recognized pathogenetic mechanisms underlying type II diabetes mellitus.     

Metformin normalizes insulin binding to monocytes from obese nondiabetic subjects and obese type II diabetic patients

In order to evaluate the in vivo effects of biguanides on the insulin receptor, we have studied insulin binding to circulating monocytes of six normal controls, eight obese nondiabetic subjects, and six obese type II diabetic patients, both before and after 4 days of treatment with the biguanide metformin (850 mg twice daily orally). Before drug administration, 125I-insulin binding to monocytes was decreased in obese subjects and diabetic patients. After metformin administration, an increase in insulin binding to peripheral monocytes was observed in seven of eight obese nondiabetic subjects (3.57 +/- 0.43 to 4.69 +/- 0.59% bound at 10(7) monocytes, mean +/- SEM, P less than 0.01) and in all diabetic patients (3.21 +/- 0.21 to 5.22 +/- 0.34, P less than 0.01). Scatchard plots indicated that the increased binding was due to an increase in the receptor number. In contrast, no significant change in insulin binding was found in normal controls after metformin administration (5.31 +/- 0.14 and 4.70 +/- 0.12). These studies indicate that metformin normalizes the binding of insulin to its receptor in obese subjects and diabetic patients. It is suggested, therefore, that the action of metformin on the insulin receptor may be one of the mechanisms of the antidiabetic effect of this drug.     

Serum C-peptide levels determine glycemic responses in type II diabetic patients treated with combined insulin and sulfonylurea agent

Type II diabetes mellitus is a heterogeneous disease. Selection of either insulin or a sulfonylurea agent in addition to diet is usually made empirically. In patients who fail to respond to either agent alone, the potential benefit of combined insulin and sulfonylurea therapy is unclear. We therefore evaluated nine poorly controlled insulin treated type II diabetic patients after addition of a sulfonylurea agent--glyburide--for four weeks. Glycosylated hemoglobin (HbA1c), serum glucose, and C-peptide responses to oral glucose were evaluated. Based on a reduction of at least 50 mg/dl in the fasting serum glucose (FSG) at the end of the first week of the combination therapy or a FSG of less than 140 mg/dl, two groups were arbitrarily identified: responders (n = 5) and nonresponders (n = 4). Clinical characteristics including mean age, weight, duration of diabetes, daily dose of insulin, and duration of insulin treatment were not statistically different between the two groups. Mean baseline FSG and HbA1c levels were also not statistically different in both groups. An improvement in mean FSG and glucose tolerance occurred in the responders at the end of four weeks of combined therapy (FSG: 291 +/- 25 vs. 189 +/- 6 mg/dl, p less than 0.05; HbA1c 10.76 +/- 0.80 vs. 9.40 +/- 0.21%, p = NS). The nonresponders had no change in glucose tolerance. The mean fasting and stimulated serum C-peptide levels were significantly higher in the responders at week 4 compared with that of the nonresponders.(ABSTRACT TRUNCATED AT 250 WORDS)     

糖尿病猴建立前后的血糖、胰岛素和C肽变化

灵长类动物的生物学特性、生理、解剖特点等与人类非常相似 ,自发性或诱发性糖尿病的疾病过程及特点与人类十分类似。作为人类糖尿病动物模型 ,灵长类动物是最佳选择。我国目前尚无利用灵长类动物建立糖尿病动物模型的报道。 1998年 10月～ 1999年 12月本研究应用链脲佐菌素(ＳＴＺ)建立恒河猴糖尿病动物模型 5只。现将成模前后的血、尿糖、胰岛素、Ｃ肽的测定结果报道如下 :一、材料和方法1.雄性成年恒河猴 5只 ,禁食 16小时后 ,称体重、测尿糖、抽静脉血做肝功能、肾功能、血脂、静脉葡萄糖耐量试验(5 0 %葡萄糖溶液 ,0 .45 ｇ/ｋｇ)和胰…     

Discrimination of type I from insulin-treated type II diabetic patients by C-peptide measurement

Summary Residual B-cell function was assessed in 61 type I and 17 type II insulin-treated diabetics by measuring plasma C-peptide concentration before and after i.v. injection of 1 mg glucagon to evaluate a possible difference in response to the test in the two groups. Fasting and poststimulatory C-peptide levels were significantly higher in type II diabetics than in type I (0.45±0.25vs 0.12±0.10 nmol/l for basal IRCP, 0.39±0.19vs 0.06±0.11 nmol/l for ΔIRCP, p<0.0001), but there was some overlap in individual values. Twenty-one percent of type 1 and 29% of type II diabtics had values in the overlap area. These percentages were reduced to 6% and 12%, respectively when only long-term (duration of diabetes more than five years) type I diabetics were considered. These data indicate that a glucagon test is useful to discriminate most type I diabetics from insulin-treated type II diabetics.     

Intravenous infusion of diarginylinsulin, an insulin analogue: effects on glucose turnover and lipid levels in insulin-treated type II diabetic patients.

Diarginylinsulin is an intermediate in the conversion of proinsulin to insulin and is usually present in small amounts in vivo in humans. This study was designed to evaluate the following in insulin-treated type II diabetic patients: (1) the feasibility of an overnight intravenous infusion of diarginylinsulin, as compared with an overnight intravenous infusion of short-acting insulin, and the degree of early morning glycemic control; and (2) the effects of diarginylinsulin and human insulin on hepatic glucose production (HGO) in the postabsorptive state and on the glucose turnover rate and peripheral insulin sensitivity during an euglycemic hyperinsulinemic clamp. Diarginylinsulin and regular human insulin maintained a comparable degree of normoglycemia during the night, without significant glucose increases in the morning. Free-diarginylinsulin and free-insulin concentrations were not significantly different, and (HGO) was 2.1 +/- 0.5 versus 2.1 +/- 0.4 mg/kg/min with diarginylinsulin and regular human insulin, respectively (NS). During the euglycemic clamp, glucose infusion rate per unit of diarginylinsulin or human insulin infused (M/I ratio) was similar, and HGO was equally suppressed with diarginylinsulin and regular human insulin. No significant differences were seen in NEFA and triglyceride levels. In conclusion, these results indicate that diarginylinsulin is as potent as regular human insulin; it is normalizes HGO in the postabsorptive state; and its hepatic and peripheral actions on glucose and lipids are comparable to those of human insulin during an euglycemic hyperinsulinemic clamp.     

Temporal pattern of pancreatic insulin and C-peptide secretion and of plasma glucose levels after nutritional stimulation.

The dependency of the secretory pattern of insulin and C-peptide on either oral ingestion of the energy substrates glucose and protein or gastric distension was determined in nine healthy male subjects. To analyze secretion dynamics, high frequency blood sampling, computed estimation of individual hormone half-lives, deconvolution of data, and pulse analysis of the deconvoluted data by the Cluster program were used. After stimulation with oral glucose and protein, baseline insulin, C-peptide, and glucose levels increased in parallel, forming two or three large increases (macropulses), with a mean duration of 63.8 min. The frequency of high frequency insulin and C-peptide pulses was unchanged, whereas a significantly increased amplitude formed the basis of insulin/C-peptide macropulses after both oral stimulations. No changes in baseline insulin/C-peptide concentrations or in amplitude or frequency were observed after a challenge with 400 mL H2O (n = 3). Gastric distension with an equal volume of H2O (400 mL) did not influence pancreatic hormone secretion. Insulin and C-peptide secretions were pulsatile, with a frequency of approximately one pulse per 12 min correlated to C-peptide pulses. When calculated by multiple regression analysis glucose, insulin and C-peptide plasma levels increased simultaneously after the challenge with either glucose or protein, suggesting a neuronal or humoral intestinal-pancreatic regulation of pancreatic hormone secretion. These findings suggest that high frequency insulin and C-peptide pulses form the basis of insulin and C-peptide plasma levels after meal stimulation.     

The insulin and glucose responses to meals of glucose plus various proteins in type II diabetic subjects

We previously have shown that ingested beef protein is just as potent as glucose in stimulating a rise in insulin concentration in type II diabetic patients. A synergistic effect was seen when given with glucose. Therefore, we considered it important to determine if other common dietary proteins also strongly stimulate an increase in insulin concentration when given with glucose. Seventeen type II (non-insulin-dependent) untreated diabetic subjects were given single breakfast meals consisting of 50 g glucose, or 50 g glucose plus 25 g protein in the form of lean beef, turkey, gelatin, egg white, cottage cheese, fish, or soy. The peripheral plasma concentrations of glucose, insulin, glucagon, alpha amino nitrogen, urea nitrogen, free fatty acids, and triglycerides were measured. Following ingestion of the meals containing protein, the plasma insulin concentration was increased further and remained elevated longer compared with the meal containing glucose alone. The relative area under the insulin response curve was greatest following ingestion of the meal containing cottage cheese (360%) and was least with egg white (190%) compared with that following glucose alone (100%). The glucose response was diminished following ingestion of the meals containing protein with the exception of the egg white meals. The peripheral glucagon concentration was decreased following ingestion of glucose alone and increased following all the meals containing protein. The alpha amino nitrogen concentration varied considerably. It was decreased after glucose alone, was unchanged after egg white ingestion, and was greatest after ingestion of gelatin. The free fatty acid concentration decrease was 4- to 8-fold greater after the ingestion of protein with glucose compared with ingestion of glucose alone.     

The effects of carbohydrate-enriched meals on glucose turnover and metabolic clearance rates of glucose in Type 2 diabetic patients

Summary The addition of fructose to natural meals elicits lower serum glucose and immunoreactive insulin responses when compared with that of sucrose and starch meals. Differences in rates of splanchnic glucose appearance and peripheral glucose disposal may be partly responsible. To evaluate the role of both parameters after different carbohydrate-enriched meals, we measured the arterialized venous blood glucose, immunoreactive insulin and gastric inhibitory polypeptide concentrations in seven Type 2 diabetic patients after ingestion of isocaloric test meals. Measurements were made in a random manner on three separate occasions. Fructose, sucrose, and bread supplementation constituted 68% of the total carbohydrate content of each meal. Rates of total glucose appearance, glucose utilization and metabolic clearance rates of glucose were determined by the D³-H-3glucose prime-continuous infusion technique. The mean fasting glucose levels were similar in the three groups. Mean peak glucose concentrations and integrated incremental areas were significantly lower (p < 0.02) after the fructose-enriched meals compared with that of either sucrose or bread. The basal arterialized venous blood glucose levels were similar in all three groups. The mean incremental integrated arterialized venous blood glucose area was significantly lower in the fructose group when compared with the sucrose (p < 0.05) and bread (p < 0.02) groups. The mean fasting gastric inhibitory polypeptide levels were similar in the three groups. However, the mean incremental integrated gastric inhibitory polypeptide areas were significantly lower in the fructose group compared with the sucrose and bread groups (p < 0.01 and p < 0.05 respectively). Basal hepatic glucose outputs were not significantly different in the three groups. After each test meal ingestion, the rate of total glucose appearance was lowest for the fructose group, intermediate for the bread group and highest for the sucrose group. However, the metabolic clearance rate did not change from the baseline despite variable arterialized venous blood glucose responses after each test meal. We conclude that the differences in glycaemic responses after carbohydrate-enriched meals cannot be ascribed solely to differences in peripheral glucose disposal in Type 2 diabetic patients. Rather, the rates of total splanchnic glucose output appear to determine the ultimate glycaemic responses after different carbohydrate-enriched meals in Type 2 diabetic patients.     

Effect of sodium salicylate on insulin secretion and blood glucose behavior in metabolically healthy and type II diabetic patients

The influence of Sodium-salicylate on insulin secretion and blood glucose behaviour was examined in 6 metabolic healthy persons and 9 type II-diabetics. Insulin secretion and blood glucose were twice examined under a combined stimulation with 100 g glucose (orally), 0.33 g glucose (Bolus injection) and 1.0 mg glucagon (i. v.) with and without a simultaneous infusion of Sodium salicylate during the whole period of examination (40 mg over 120 min). Sodium salicylate effected in type II-diabetics and metabolic healthy persons higher insulin levels. Qualitative differences of the insulin secretion pattern were not to be seen. In spite of higher insulin levels blood glucose was not influenced by Sodium salicylate. It is discussed if the results could be explained by a direct effect of Sodium salicylate on the cells ore on the metabolism of insulin and the gluconeogenesis.     

Plasma homocysteine after insulin infusion in type II diabetic patients with and without methionine intolerance.

BACKGROUND: A high prevalence of hyperhomocysteinemia has been reported in type II diabetic patients with documented vascular disease; hence the hypothesis that hyperhomocysteinemia may contribute to overall mortality in diabetic patients. The link between insulin and homocysteine metabolism has not been completely clarified yet; in particular, only few data are available on the effects of insulin in vivo on homocysteine metabolism in the presence of abnormalities of sulphur amino acid metabolism (methionine intolerance). MATERIALS AND METHODS: To establish whether methionine intolerance and which of its determinants could influence total plasma homocysteine in response to insulin infusion in vivo in type II diabetic patients, we submitted 18 patients (Group A) with normal and 18 patients with abnormal (hyperhomocysteinemia) (Group B) response to oral methionine load to a glucose/clamp study. At time 0, and 30, 60 and 120 minutes after hyperinsulinemia, homocysteine and methionine plasma levels were assessed. In order to evaluate the cause of methionine intolerance, all patients were assayed for fasting homocysteine-cysteine ratio (as a marker of suspected heterozygosis for cystathionine-beta-synthase deficit), MTHFR C (677)T status and homocysteine-related vitamin status (serum vitamin B (6) [PLP], vitamin B (12) and folate). RESULTS: After hyperinsulinemia, plasma methionine was reduced (by about - 30 % at 120 minutes vs. basal values) within both groups, whereas tHcy tend to decrease in group A following insulin administration (up to - 6.6 +/- 3.6 % vs. basal values at 120 minutes) with a significantly higher variability, while in patients with "methionine intolerance" (group B) tHcy tended to increase (up to + 29.05 +/- 8.3 % vs. basal values at 120 min from the clamp). Serum folic acid (7.45 +/- 2.8 vs. 4.82 +/- 2.5 nmol/L, p < 0.05), Vit. B (12) (348 +/- 78 vs. 242 +/- 65 pmol/L, p < 0.05) and PLP (84.1 +/- 23.6 vs. 50.6 +/- 32.4 nmol/L; p < 0.01) were significantly higher in group A than in group B; PLP levels significantly correlated with homocysteine after 4 h methionine load (n = 36; r = - 0.327, p < 0.05); group A showed also a significantly lower prevalence of suspected heterozygosis for cystathionine-beta-synthase deficit (1/18 [11.1 %] vs. 5/18 [33.3 %], p < 0.05) and MTHFR T allele presence (4/18 [22.2 %] vs. 11/18 [61.1 %], p < 0.01). A stepwise regression analysis with tHcy plasma level variations (event A = reduction; event B = increase) as the dependent variable showed that low serum folate and PLP levels and presence of MTHFR T allele were the variables associated with insulin-induced tHcy increase. CONCLUSIONS: Methionine intolerance may influence the effect of insulin administration on plasma homocysteine in patients affected by type 2 diabetes. To prevent a possible acute (and repeated) hyperhomocysteinemia due to insulin administration in cases of methionine intolerance, it may be useful to assess the presence of methionine intolerance (tHcy after oral methionine loading) and Hcy-related vitamin status in all patients due to be subjected to insulin therapy.     

Relationship between hepatic/visceral fat and hepatic insulin resistance in nondiabetic and type 2 diabetic subjects

BACKGROUND AND AIMS: Abdominal fat accumulation (visceral/hepatic) has been associated with hepatic insulin resistance (IR) in obesity and type 2 diabetes (T2DM). We examined the relationship between visceral/hepatic fat accumulation and hepatic IR/accelerated gluconeogenesis (GNG). METHODS: In 14 normal glucose tolerant (NGT) (body mass index [BMI] = 25 +/- 1 kg/m(2)) and 43 T2DM (24 nonobese, BMI = 26 +/- 1; 19 obese, BMI = 32 +/- 1 kg/m(2)) subjects, we measured endogenous (hepatic) glucose production (3-(3)H-glucose) and GNG ((2)H(2)O) in the basal state and during 240 pmol/m(2)/min euglycemic-hyperinsulinemic clamp, and liver (LF) subcutaneous (SAT)/visceral (VAT) fat content by magnetic resonance spectroscopy/magnetic resonance imaging. RESULTS: LF was increased in lean T2DM compared with lean NGT (18% +/- 3% vs 9% +/- 2%, P < .03), but was similar in lean T2DM and obese T2DM (18% +/- 3% vs 22% +/- 3%; P = NS). Both VAT and SAT increased progressively from lean NGT to lean T2DM to obese T2DM. T2DM had increased basal endogenous glucose production (EGP) (NGT, 15.1 +/- 0.5; lean T2DM, 16.3 +/- 0.4; obese T2DM, 17.2 +/- 0.6 micromol/min/kg(ffm); P = .02) and basal GNG flux (NGT, 8.6 +/- 0.4; lean T2DM, 9.6 +/- 0.4; obese T2DM, 11.1 +/- 0.6 micromol/min/kg(ffm); P = .02). Basal hepatic IR index (EGP x fasting plasma insulin) was increased in T2DM (NGT, 816 +/- 54; lean T2DM, 1252 +/- 164; obese T2DM, 1810 +/- 210; P = .007). In T2DM, after accounting for age, sex, and BMI, both LF and VAT, but not SAT, were correlated significantly (P < .05) with basal hepatic IR and residual EGP during insulin clamp. Basal percentage of GNG and GNG flux were correlated positively with VAT (P < .05), but not with LF. LF, but not VAT, was correlated with fasting insulin, insulin-stimulated glucose disposal, and impaired FFA suppression by insulin (all P < .05). CONCLUSIONS: Abdominal adiposity significantly affects both lipid (FFA) and glucose metabolism. Excess VAT primarily increases GNG flux. Both VAT and LF are associated with hepatic IR.     

Plasma C-peptide and serum insulin antibodies in diabetic patients receiving pancreatic transplants

Summary Plasma C-peptide and serum insulin antibody levels were determined in 5 diabetic patients undergoing vascularized pancreatic transplantation. The grafts functioned well at first and exogenous insulin could be withdrawn, but one to 7 weeks later the grafts were rejected. After the transplantation there was an increase in the fasting plasma C-peptide level, and B-cell stimulation with glucose or glucagon evoked a C-peptide response. Healing of ischaemic damage was reflected in an increase in the C-peptide level. During graft rejection the C-peptide level fell. Measurement of plasma C-peptide levels provides a direct index of the B-cell function of the pancreatic graft. After transplantation the insulin antibody level fell exponentially, with an apparent half life of 10–11 days, whereas the level of total IgG was variable. The results indicate that formation of insulin antibodies ceases immediately on removal of the immunogenic stimulus, that is, on withdrawal of xenogeneic insulin.     

Plasma amino acid profiles are associated with insulin,C-peptide and adiponectin levels in type 2 diabetic patients

Objectives:

Plasma-free amino acid (PFAA) profiles have been associated with a future risk of developing diabetes or cardiovascular disease in nondiabetic subjects. These PFAA alterations might predominantly result from the metabolic shift caused by insulin resistance and visceral fat deposition. The variety of PFAA profiles within diabetic subjects is not well researched. In this study, we focused on type 2 diabetic subjects and examined the association between PFAA profiles and insulin- and glucose-related variables.

Methods:

Fifty-one Japanese subjects diagnosed with type 2 diabetes were recruited from an outpatient clinic. The plasma concentrations of 21 amino acids; glucose-related markers including glucose, hemoglobin A1c (HbA1c), glycoalbumin and 1,5-anhydroglucitol; insulin-related markers including insulin, C-peptide, and the homeostasis model assessment of insulin resistance; and adipocytokines including adiponectin and leptin were determined. The association of PFAA and other metabolic profiles were analyzed, and stratified analyses of the PFAAs and clinical characteristics were performed according to the fasting plasma insulin and HbA1c levels. In addition, the PFAA indices that correlate to visceral fat obesity were evaluated.

Results:

Although strong correlations between PFAAs and glucose-related markers were not observed, several amino acids (branched-chain amino acids, tryptophan, alanine, tyrosine, glutamate and proline) and PFAA indices that evaluate visceral obesity were highly correlated with insulin-related markers and adiponectin (P<0.001). In the group of diabetic patients with hyperinsulinemia, the amino acid levels were significantly increased, which generally demonstrated good concordance with insulin-related markers and adiponectin levels.

Conclusions:

The PFAA profiles in diabetic patients were strongly associated with hyperinsulinemia and hypoadiponectinemia, which might become risk evaluation factors for the development of cardiovascular diseases.     

Impaired glucose disposal following mild hypoglycemia in nondiabetic and type I diabetic humans.

Insulin-mediated glucose disposal was studied immediately prior to and following moderate hypoglycemia in nondiabetic subjects and subjects with insulin-dependent (type I) diabetes mellitus (IDDM), the latter having varying epinephrine secretory capacities. Plasma insulin concentration was fixed throughout the study at approximately 300 to 400 pmol/L to avoid effects of waning insulin action and plasma glucose was clamped at either 5 mmol/L (euglycemic control) or at 3.1 mmol/L (hypoglycemic) periods of 120 minutes. Baseline (clamp 1) and postexperiment (clamp 2) periods were assessed for net glucose disposal (as a function of the exogenous glucose infusion rate) and glucose kinetics using 3H-glucose. In normal subjects, glucose disposal increased progressively by 132% during control studies but only by 57% with intervening hypoglycemia (P less than .005). Similarly, 33% during hypoglycemia, P less than .025). These changes were mediated by reduction of whole-body glucose uptake (rate of glucose disappearance [Rd], [3H]-3-glucose) and metabolic clearance rates with comparable suppression of hepatic glucose production in both groups. The increase in plasma free-fatty acids (FFA) following hypoglycemia was modest but greater in subjects with IDDM (P less than .01), whereas IDDM had reduced concentrations of epinephrine (P less than .01) and glucagon (P less than .005) during hypoglycemia. In subjects with IDDM but not in normal subjects, the change in posthypoglycemia glucose disposal was inversely correlated with the increase in plasma norepinephrine (R2 = .54, P less than .004) and epinephrine (R2 = .32, P less than .04). Glucose disposal did not correlate with other counterregulatory hormones, plasma FFA, or antecedent glycemic control.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of corneal endothelial cell changes after phacoemulsification between type 2 diabetic and nondiabetic patients

The aim of this study is to compare the endothelial cell density (ECD) and morphology between diabetic mellitus (DM) and nondiabetic patients at 1 year after phacoemulsification in operated eyes and nonoperated eyes.Evaluation was performed in 28 patients (56 eyes) with type 2 diabetes and 37 patients (74 eyes) without diabetes who underwent 1-year interval cataract surgery. Using a noncontact specular microscope and Scheimpflug rotating camera, corneal parameters were analyzed before and 1 year after surgery. Subgroups analysis was performed based on a disease duration 10 years and HbA1c concentration 7% and Pearson correlation analysis was performed.The mean change in ECD at 1 year after surgery was 13.28% in the DM group and 11.40% in the control group. In the fellow nonoperated eyes, the mean change was 4.47% and 3.63% in the DM and control groups, respectively. There was no significant difference in postoperative ECD, coefficient of variance, hexagonality, and central corneal thickness between 2 groups. In the subgroup analysis, the long disease duration DM group (≥10 years) had a significantly greater ECD loss than the control and short disease duration DM groups (<10 years). Blood urea nitrogen (BUN) showed a significant correlation with postoperative ECD change (r = −0.474, P = .011).The diabetic group with a longer disease duration showed significantly greater ECD decrease compared to the nondiabetic group and BUN correlated with ECD changes after phacoemulsification. Postoperative ECD loss may be high if the disease duration is long or if the BUN level is high.