Efficacy and Safety of Alogliptin in Elderly Patients With Type 2 Diabetes Mellitus.

BACKGROUND: In Japan, with increasing age of the population, diabetic patients often become in need of hemodialysis due to diabetic nephropathy, and thus there is a demand for development of diabetic treatments that take into account renal effects in the elderly. No previous studies of alogliptin had focused on Japanese elderly subjects; we therefore assessed the effects of alogliptin in elderly individuals using available data. METHODS: Laboratory data were compiled for 1 year at intervals of 3 months following the start of alogliptin treatment. The subjects were divided into three groups by age: < 65 years (n = 110), 65 - 74 years (n = 87), and ≥ 75 years (n = 93). Laboratory values in comparison with baseline were compared within groups at various time points, and changes from baseline were compared among the different groups. RESULTS: Hemoglobin A1c (HbA1c) levels decreased significantly from baseline values in all groups at and after month 3: the change at month 12 was -0.74±1.45% for the age group < 65, -0.47±1.02% for the age group 65 - 74, and -0.42±1.11% for the age group ≥ 75. The 12-month change in estimated glomerular filtration rate (eGFR) was -6.5 ± 12.0 for the age group < 65, -2.0 ± 8.4 for the age group 65 - 74, and -1.5 ± 10.0 for the age group ≥ 75; the reduction in the age group < 65 was significant, whereas the reduction in the age groups ≥ 65 was not. CONCLUSIONS: Alogliptin significantly lowers HbA1c levels in the elderly and can be used without posing any safety issues, including renal effects, thus contributing to safe blood glucose control in clinical practice.

Efficacy and Safety of Adding Sitagliptin in Type 2 Diabetes Patients on Insulin: Age-Stratified Comparison at One Year in the ASSIST-K Study.

BACKGROUND: Sitagliptin, the first dipeptidyl peptidase-4 inhibitor, has demonstrated efficacy and safety as monotherapy and as add-on therapy to oral antidiabetic agents or insulin. However, there have been few reports about sitagliptin in elderly patients. The ASSIST-K observational study was performed in patients with type 2 diabetes mellitus (T2DM) receiving sitagliptin as add-on therapy to insulin. Changes of hemoglobin A1c (HbA1c), body weight, and the estimated glomerular filtration rate (eGFR), as well as adverse events, were investigated over 12 months in age-stratified groups. METHODS: Among outpatients with T2DM treated at member institutions of Kanagawa Physicians Association, those starting sitagliptin as add-on therapy to insulin were followed for 12 months. HbA1c (National Glycohemoglobin Standardization Program), body weight, and eGFR were the efficacy endpoints, while adverse events were investigated to assess safety. Patients were stratified into three age groups (≤ 64 years, 65 - 74 years, and ≥ 75 years) for comparison of the endpoints. RESULTS: Among 937 patients on insulin before starting sitagliptin, 821 patients were analyzed after excluding those without HbA1c data at baseline and 12 months. The two groups of elderly patients (65 - 74 years and ≥75 years) had more complications and their HbA1c was lower at initiation of sitagliptin therapy. The dose of sitagliptin, daily number of insulin injections, and number of concomitant oral antidiabetic agents were all lower in the elderly patients. HbA1c showed a significant decrease after initiation of sitagliptin in all age groups, and there were no significant intergroup differences in the change of HbA1c at 12 months. Body weight did not change significantly in any group. eGFR decreased significantly in all groups, with no significant intergroup differences at 12 months. Regarding adverse events, there were no significant intergroup differences in the incidence of severe hypoglycemia, gastrointestinal symptoms, or constipation. CONCLUSIONS: Despite baseline differences in demographic factors and medications, sitagliptin showed good efficacy and safety in all age groups of patients receiving it as add-on therapy to insulin during routine management of T2DM. Adding sitagliptin to insulin achieves similar efficacy and safety outcomes at 12 months in both elderly and non-elderly T2DM patients.

Effectiveness of Ipragliflozin for Reducing Hemoglobin A1c in Patients With a Shorter Type 2 Diabetes Duration: Interim Report of the ASSIGN-K Study.

BACKGROUND: Ipragliflozin is a selective sodium glucose co-transporter 2 inhibitor. The ASSIGN-K study is investigating the efficacy and safety of ipragliflozin for type 2 diabetes mellitus (T2DM) in the real-world clinical setting. METHODS: Japanese T2DM patients with inadequate glycemic control despite diet and exercise with/without pharmacotherapy were enrolled in an investigator-driven, multicenter, prospective, observational study examining the efficacy and safety of ipragliflozin treatment (50 mg/day for 52 weeks). We performed interim analysis after 24 weeks. RESULTS: In 367 patients completing 24-week ipragliflozin therapy, hemoglobin A1c (HbA1c) decreased significantly from 8.07% at baseline to 7.26% in week 24 (P < 0.001). The change in HbA1c from treatment initiation to week 24 was -0.88% in patients < 65 years old versus -0.55% in those ≥ 65 years and -0.92% in men versus -0.70% in women (all P < 0.001). When baseline HbA1c was < 7%, 7% to < 8%, and ≥ 8%, the change was -0.18%, -0.45%, and -1.48%, respectively (P = 0.5352, P < 0.001, and P < 0.001, respectively). When baseline body mass index (BMI) was < 25, 25 to < 30, and ≥ 30, the change was -1.05%, -0.65%, and -0.87%, respectively (all P < 0.001). Multiple regression analysis showed that HbA1c decreased more in patients with a higher baseline HbA1c or shorter duration of diabetes. An HbA1c < 7% was achieved in 33.3% of the patients, and their baseline HbA1c was significantly lower than that of patients failing to achieve it (P < 0.001). Adverse events (AEs) occurred in 106/451 patients (23.5%), including 29.1% of patients aged 65 or older. Common AEs were vulvovaginal candidiasis (3.1%) and genital pruritus (1.8%). Serious AEs included urinary tract infection, unstable angina, and ketosis, which occurred in patients who did not suspend medication during acute illness. CONCLUSIONS: Ipragliflozin significantly improved HbA1c in T2DM patients with inadequate glycemic control. Improvement in HbA1c was significant irrespective of age, sex, baseline HbA1c, or BMI, but efficacy was greater with a higher baseline HbA1c and shorter duration of diabetes. For safe continuation of treatment, patients should be advised to suspend medication during acute illness.

Ipragliflozin Improves Glycemic Control and Decreases Body Fat in Patients With Type 2 Diabetes Mellitus.

BACKGROUND: Ipragliflozin, a sodium-glucose transporter 2 inhibitor, was administered to patients with type 2 diabetes mellitus for 24 weeks to evaluate its effect on glycemic control and body composition. METHODS: This was an investigator-initiated multicenter prospective intervention study in which ipragliflozin (50 mg) was administered once daily and glycemic control, blood pressure, body weight (BW), body composition (measured by a biological impedance method), the lipid profile, and adverse events were evaluated after 4, 12, and 24 weeks of treatment. RESULTS: Efficacy and safety up to 24 weeks of ipragliflozin therapy were analyzed in 367 patients and 451 patients, respectively. Hemoglobin A1c decreased significantly from 8.07% at the start of ipragliflozin therapy to 7.26% in week 24 (P < 0.001). Fasting and postprandial blood glucose levels were significantly reduced by ipragliflozin. In week 24, there were significant decreases from baseline in BW (-2.6 kg), waist circumference (-2.9 cm), and body fat mass (-1.9 kg) (P < 0.001). The body water mass and mineral mass were decreased significantly by 0.5 and by 0.1 kg, respectively (P < 0.001), whereas the protein mass did not change significantly. Intracellular water mass did not change significantly, whereas extracellular water mass showed a significant decrease of 0.5 kg (P < 0.001). Muscle mass did not change in the upper and lower limbs, but that of the trunk decreased significantly (P < 0.001). There was a significant decrease in the fasting triglyceride level and a significant increase in fasting high-density lipoprotein cholesterol level, while low-density lipoprotein cholesterol was unchanged. Adverse events occurred in 23.5% of the patients, with a high frequency of genital infections, such as vulvovaginal candidiasis (3.1%) and genital pruritus (1.8%). Adverse drug reactions were noted in 13.7% of the patients. CONCLUSIONS: Administration of ipragliflozin for 24 weeks improved glycemic control and decreased BW. Reduction of body fat accounted for more than 70% of the total weight loss and reduction of extracellular water accounted for about 20%.

Factors Influencing Changes in Hemoglobin A1c and Body Weight During Treatment of Type 2 Diabetes With Ipragliflozin: Interim Analysis of the ASSIGN-K Study.

BACKGROUND: Ipragliflozin is a selective sodium glucose co-transporter 2 (SGLT2) inhibitor that blocks glucose reabsorption in the proximal tubules. SGLT2 inhibitors are expected to be effective in patients with insulin resistance and obesity, but it is important to select treatment according to patient background factors that minimizes the risk of adverse events. There have been a limited number of investigations into the relationship between the clinical efficacy (reducing hemoglobin A1c (HbA1c) and body weight (BW)) or safety of SGLT2 inhibitors and patient characteristics. METHODS: ASSIGN-K is an investigator-initiated, multicenter, prospective observational study examining the efficacy and safety of ipragliflozin (50 - 100 mg/day for 52 weeks) in Japanese patients with type 2 diabetes mellitus (T2DM) who had inadequate glycemic control with HbA1c ≥ 6.0% (National Glycohemoglobin Standardization Program) despite diet and exercise therapy or diet and exercise plus antidiabetic drug therapy. We conducted an interim analysis of the relationship between changes in HbA1c or BW and characteristics in patients who had been on treatment for more than 12 weeks. RESULTS: In 257 patients completing 12 weeks of treatment, HbA1c decreased significantly from 8.23% to 7.55% (-0.68%, P < 0.01). The change in HbA1c after 12 weeks was -0.17%, -0.33%, and -1.16% when baseline HbA1c was < 7%, 7% to < 8%, and ≥ 8%, respectively (P < 0.05, P < 0.01, and P < 0.01, respectively), and -1.30%, -0.62%, and -0.62% when baseline body mass index (BMI) was < 25, 25 to < 30, and ≥ 30, respectively (all P < 0.01). Stratified analysis showed that age, gender, or BMI did not have a significant influence on the improvement in HbA1c. Multiple regression analysis showed that reduction in HbA1c was greater as baseline HbA1c increased and the duration of diabetes decreased. A higher baseline HbA1c was associated with less weight loss. CONCLUSIONS: Ipragliflozin significantly improved HbA1c in patients with T2DM. HbA1c improved more when baseline HbA1c was higher and the duration of diabetes was shorter, suggesting that current treatment policies for diabetes could be re-examined.

Correction: Efficacy and Safety of Ipragliflozin in Japanese Patients With Type 2 Diabetes: Interim Outcome of the ASSIGN-K Study.

[This corrects the article DOI: 10.14740/jocmr2417w.].

Efficacy and Safety of Ipragliflozin in Japanese Patients With Type 2 Diabetes: Interim Outcome of the ASSIGN-K Study.

BACKGROUND: Ipragliflozin is a sodium-glucose co-transporter 2 inhibitor that can improve glycemic control and reduce body weight and blood pressure in patients with type 2 diabetes mellitus (T2DM). We evaluated the efficacy and safety of ipragliflozin in the real-world clinical setting, with a focus on the changes of body composition up to 3 months of treatment. METHODS: This was a prospective multicenter interventional trial. We investigated changes of the blood pressure, body composition, blood glucose, hemoglobin A1c (HbA1c), ketone bodies, lipids, and insulin after treatment with ipragliflozin (50 - 100 mg/day) for 12 weeks in Japanese patients with T2DM who showed poor glycemic control despite receiving diet and exercise therapy with or without oral antidiabetic drugs for more than 12 weeks. RESULTS: Two hundred and fifty-seven subjects were included in the efficacy analysis up to 12 weeks of treatment and 301 subjects were included in the safety analysis. From baseline to 12 weeks, HbA1c showed a change of -0.68% (95% confidence interval (CI): -0.83, -0.53) and fasting blood glucose showed a change of -23.9 mg/dL (95% CI: -30.5, -17.2), with both parameters displaying a significant reduction (P < 0.001). The difference of body weight from baseline was -1.82 kg (95% CI: -2.14, -1.50), and it also showed significant reduction (P < 0.001). Analysis of body composition revealed that body fat changed by -1.46 kg (95% CI: -1.79, -1.14, P < 0.001) and body water changed by -0.37 kg (95% CI: -0.60, -0.14, P < 0.01). Laboratory tests demonstrated improvement of liver function and the lipid profile. Adverse events (AEs) occurred in 22.6% of the subjects, with frequent events being vulvovaginal candidiasis in 2.7% and cystitis in 2.0%. Serious AEs occurred in three subjects. CONCLUSIONS: In patients with T2DM, ipragliflozin improved glycemic control after 1 month of treatment and caused weight loss by reducing body fat more than body water.

Efficacy and Safety of Alogliptin in Patients With Type 2 Diabetes: Analysis of the ATTAK-J Study.

BACKGROUND: Dipeptidyl peptidase-4 (DPP-4) inhibitors have been shown to reduce hemoglobin A1c (HbA1c) in patients with type 2 diabetes, but the reduction varies between patients and adequate glycemic control may not be achieved. We evaluated the efficacy and safety of the DPP-4 inhibitor alogliptin in the real clinical setting, and analyzed factors associated with the improvement of HbA1c by alogliptin treatment. METHODS: A retrospective observational study was performed in patients with type 2 diabetes attending hospitals or clinics belonging to the Kanagawa Physicians Association who received treatment with alogliptin for 1 year or longer. Patients using insulin were excluded from the study. The efficacy endpoints were HbA1c (National Glycohemoglobin Standardization Program value), blood glucose (fasting/postprandial), body weight, blood pressure (systolic/diastolic), liver function (glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, and γ-glutamyl transpeptidase), kidney function (serum creatinine and estimated glomerular filtration rate), serum lipids (total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides), and serum amylase. Adverse events were compiled to assess safety. RESULTS: Of 330 patients whose case records were collected, 27 patients were excluded for protocol violations, leaving 303 patients to form the full analysis set. Compared with baseline, HbA1c showed a decrease by 0.54±1.22% (mean ± standard deviation) after 12 months of alogliptin treatment. Factor analysis demonstrated that the change of HbA1c after 12 months was significantly influenced by the baseline HbA1c level, duration of diabetes, concomitant use of sulfonylureas, and compliance with diet therapy. In addition, there was a significant reduction of total cholesterol, low-density lipoprotein cholesterol, and the estimated glomerular filtration rate after 12 months of alogliptin treatment, as well as a significant increase in serum creatinine. No significant changes of body weight, blood pressure, or liver function were observed. Symptoms of hypoglycemia occurred in two patients (0.6%). CONCLUSIONS: Alogliptin displayed a significant hypoglycemic effect and excellent safety in routine clinical use. Factors influencing the change of HbA1c with alogliptin therapy may include the HbA1c at the start of treatment, the duration of diabetes, use of sulfonylureas, and compliance with diet therapy.

Factors Predicting Therapeutic Efficacy of Combination Treatment With Sitagliptin and Insulin in Type 2 Diabetic Patients: The ASSIST-K Study.

BACKGROUND: It is unclear whether dipeptidyl peptidase-4 inhibitors decrease hemoglobin A1c (HbA1c) in a glucose-dependent manner in patients on insulin therapy who have impaired insulin secretion. This study investigated factors influencing the efficacy of sitagliptin when used concomitantly with insulin to treat type 2 diabetes mellitus (T2DM) in the real-world setting. METHODS: A retrospective study was conducted of 1,004 T2DM patients at 36 Japanese clinics associated with the Diabetes Task Force of the Kanagawa Physicians Association. Eligible patients had been on insulin for at least 6 months, with a baseline HbA1c of 7.0% (53 mmol/mol) or higher. Baseline characteristics and laboratory data from 495 patients were subjected to multiple regression analysis to identify factors influencing the change of HbA1c. RESULTS: Most patients (n = 809) received sitagliptin at a dose of 50 mg. In the 1,004 patients, HbA1c decreased by 0.74% (6 mmol/mol) and body weight increased by 0.1 kg after 6 months of combination therapy. Multiple regression analysis showed that a higher baseline HbA1c, older age, and lower body mass index influenced the change of HbA1c after 6 months. Hypoglycemic symptoms occurred in 7.4%, but none were severe. CONCLUSIONS: These results emphasize the importance of a higher HbA1c at the commencement of sitagliptin therapy in patients on insulin. Glucose-dependent suppression of glucagon secretion by sitagliptin may be useful in patients with impaired insulin secretion. Sitagliptin can be used concomitantly with insulin irrespective of the insulin regimen, duration of insulin treatment, and concomitant medications.

Two-year assessment of the efficacy and safety of sitagliptin in elderly patients with type 2 diabetes: Post hoc analysis of the ASSET-K study.

BACKGROUND: There have only been a few reports about use of dipeptidyl peptidase 4 (DPP-4) inhibitors in elderly patients with type 2 diabetes mellitus (T2DM), suggesting that the safety of these agents has not been sufficiently demonstrated. We performed a comparative review of the efficacy and safety of sitagliptin for Japanese patients with T2DM managed in the real-world clinical setting. METHODS: An age-stratified analysis was performed of 831 patients who were treated with sitagliptin for 2 years. Parameters assessed included the hemoglobin A1c (HbA1c), body weight, serum creatinine, and adverse events. HbA1c and the incidence of hypoglycemia were also evaluated in patients treated with sitagliptin and a sulfonylurea (SU), who were divided into three age groups (<65 years, 65-74 years, and ≥75 years). RESULTS: Comparison of glycemic control parameters, laboratory values, and adverse events revealed significant improvement of HbA1c, casual postprandial plasma glucose, and fasting plasma glucose in each age group with no change in body weight. Serum creatinine increased significantly in all age groups. Hypoglycemia only occurred in patients who received combined treatment with an SU and sitagliptin, and there was no age-related difference in its incidence. CONCLUSIONS: HbA1c was improved by 2 years of sitagliptin therapy in all three age groups, and age did not seem to influence the incidence of hypoglycemic events. These results confirm the efficacy and safety of sitagliptin in patients ≥ 75 years old, suggesting that it is also useful for treating elderly patients with T2DM.

Effects of irbesartan on serum uric acid levels in patients with hypertension and diabetes.

BACKGROUND: Hyperuricemia has been proposed to be a risk factor for cardiovascular disease and chronic kidney disease. Since diabetes is often complicated by hypertension and hyperuricemia, efficient therapeutic strategy against these two complications is very important in diabetic treatment. It has been reported that the antihypertensive drug, irbesartan, inhibits the renal uric acid reabsorptive transporters, URAT1 and GLUT9; this result suggests that irbesartan decreases serum uric acid level (SUA). SUBJECTS AND METHODS: A retrospective study of 107 patients with hypertension and diabetes was performed to analyze the effects of irbesartan on blood pressure, estimated glomerular filtration rate (eGFR), and SUA. The follow-up period was 6-12 months. Seventy percent of the patients were diagnosed with diabetic nephropathy stage II-IV. We excluded patients treated with drugs that influenced SUA. The multiple logistic regression analysis was introduced to identify the relative factors for SUA decline. The time-dependent SUA changes were examined in a mixed-linear model. RESULTS: Irbesartan reduced blood pressure significantly after 1, 6, and 12 months' treatment. No subject showed significant change in eGFR from baseline level throughout the period. The multiple logistic regression analysis revealed that SUA baseline significantly influenced SUA decline after 6-12 months. In patients whose SUA baseline was ≥5.9 mg/dL, the SUA was significantly decreased from 6.6±0.16 mg/dL to 6.2±0.16 mg/dL (P=0.010), after 12 months' irbesartan treatment. In the SUA baseline <5.9 mg/dL group, the SUA did not show significant change over the monitoring period. CONCLUSION: Our results demonstrate that irbesartan reduces the risk of hyperuricemia. No decline in renal function was observed after the initiation of irbesartan treatment. The present report determines the criteria of SUA baseline for introducing an antihyperuricemic effect using irbesartan. Its antihypertensive effect coupled with SUA decline would be effective for the treatment of hypertension complicated by hyperuricemia.

Safety and efficacy of adding sitagliptin to insulin in patients with type 2 diabetes: the ASSIST-K study.

We retrospectively studied more than 1000 patients with type 2 diabetes attending 36 Japanese clinics to investigate the efficacy and safety of adding sitagliptin to various insulin regimens. We found that the treatment with add-on sitagliptin for 6-months was effective, irrespective of the type or dose of concomitant insulin.

Pleiotropic effects of sitagliptin in the treatment of type 2 diabetes mellitus patients.

BACKGROUND: Sitagliptin is a DPP-4 inhibitor that became available for use in Japan three years ago. This study was conducted to identify the pleiotropic effects of sitagliptin other than blood glucose lowering in Japanese type 2 diabetes mellitus patients. METHODS: A retrospective, observational study of 940 type 2 diabetes mellitus patients was conducted. The primary outcome measures were HbA1c, blood pressure, and lipid profiles measured at 0, 4, and 12 weeks of sitagliptin therapy. RESULTS: After 12 weeks of sitagliptin treatment, compared with baseline, HbA1c decreased 0.64% ± 0.86%; systolic blood pressure (SBP) and diastolic blood pressure (DBP) decreased significantly; and serum creatinine (Cr) and uric acid (UA) levels were mildly but significantly elevated. A correlation analysis of the changes in systolic blood pressure, diastolic blood pressure, creatinine, and uric acid (ΔSBP, ΔDBP, ΔCr, ΔUA) from baseline to 12 weeks showed significant negative correlations between ΔSBP and ΔCr, ΔSBP and ΔUA, and ΔDBP and ΔCr. Total cholesterol and postprandial triglycerides were significantly decreased at both 4 and 12 weeks. Alkaline phosphatase (ALP) decreased significantly, and there was a significant positive correlation between changes in ALP and HbA1c. CONCLUSIONS: Sitagliptin seems to be effective not only in lowering blood glucose but also in lowering blood pressure, lipid, and ALP levels. Sitagliptin appears to contribute to a Na-diuretic action due to GLP-1.

Cross-sectional survey of diabetic neuropathy in Kanagawa and clinical significance of a touch test using tissue paper.

UNLABELLED: Aims/Introduction: The prevalence of diabetes mellitus is increasing rapidly in Japan, and diabetic neuropathy is a major factor decreasing diabetic patients' quality of life, as well as a risk factor for sudden death. The present study aimed to determine the prevalence of diabetic neuropathy and raise awareness about it among patients and their physicians. MATERIALS AND METHODS: Diabetic outpatients (N = 5077) at 249 medical institutions within Kanagawa Prefecture, Japan, were surveyed by questionnaire and underwent foot examinations. The questionnaire included 10 questions about sensory abnormalities of both feet, muscle cramps and autonomic symptoms. Foot examinations included testing for vibratory perception of the medial malleolus, Achilles tendon reflexes and touch sensation of the bottom of the great toe using tissue paper. RESULTS: Of the 5077 patients surveyed, 70.4% reported symptoms. Overall, 75.4% of the patients underwent vibratory perception testing, of whom 44.9% had abnormal thresholds (≤10 s). On the tissue paper touch test, performed in 94.6% of patients, 11.9% had no touch sensation. Of the 2803 type 2 diabetic patients with known background factors who underwent foot examinations, 49.4% had diabetic neuropathy. There was a high prevalence of diabetic neuropathy (36.1%) in patients with <5-year history. Of the patients with no touch sensation on the tissue paper test, 81.3% had diabetic neuropathy. CONCLUSIONS: The present study identified the prevalence of diabetic neuropathy in Kanagawa Prefecture. The tissue paper test is a simple and excellent method of evaluating decreased superficial sensation that can help evaluate the severity of diabetic neuropathy. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00174.x, 2011).

Efficacy and safety of sitagliptin monotherapy and combination therapy in Japanese type 2 diabetes patients.

UNLABELLED: (J Diabetes Invest, doi: 10.1111/j.2040-1124.2012.00221.x, 2012) Aims/Introduction: To determine the efficacy and safety of sitagliptin monotherapy and combination therapy in Japanese type 2 diabetes patients after 3 months' therapy. MATERIALS AND METHODS: A retrospective, observational study of 741 type 2 diabetes patients was carried out; 110 received sitagliptin monotherapy, and 631 received combination therapy with sitagliptin when other oral medications were insufficient. The primary outcome measure was glycated hemoglobin (HbA1c) measured at 0, 4 and 12 weeks of sitagliptin therapy. RESULTS: In the monotherapy and combination therapy groups, HbA1c decreased significantly after 12 weeks. Target HbA1c (<7%) was achieved in 39.1% overall. On logistic regression analysis, baseline HbA1c was the strongest contributing factor for achieving target HbA1c; baseline body mass index and duration of diabetes were also significant factors. A total of 82 patients (11%) were unresponsive to sitagliptin. These patients' baseline body mass index was significantly higher and their baseline HbA1c was significantly lower than those of patients who responded to sitagliptin. The most commonly co-administered drugs were sulfonylureas (508 patients). In these patients, the dose of sulfonylurea decreased with time. In 66 patients whose sulfonylurea dosage was reduced when sitagliptin was started, HbA1c and bodyweight decreased significantly after 12 weeks. A total of 24 patients receiving sulfonylureas had mild hypoglycemia, but none discontinued sitagliptin. CONCLUSIONS: Sitagliptin was effective and safe as both monotherapy and combination therapy in Japanese type 2 diabetes patients. When sulfonylureas were ineffective, sitagliptin improved glycemic control. In patients whose sulfonylurea dose was reduced at the start of sitagliptin, blood glucose improved and bodyweight decreased after 12 weeks.