Published papers

Introduction: It is challenging for pregnant women with type 1 diabetes to maintain optimum glucose level to attain good neonatal outcomes. This study evaluated the efficacy of sensor-augmented insulin pump (SAP) with a predictive low-glucose suspend (PLGS) system in pregnant Japanese women with type 1 diabetes. Materials and methods: SAP with PLGS was used in 11 of the 22 women with type 1 diabetes who delivered between 2011 and 2021 at the two medical institutions in Japan. Glucose management, insulin delivery suspension time (IST) and neonatal outcomes were retrospectively studied. Results: In SAP with PLGS cases (n = 11), average glycated hemoglobin levels were < 6.5% throughout the pregnancy, and the time in range (TIR, 63–140 mg/dl) was > 70% in the second and third trimesters. PLGS was safely used without inducing ketoacidosis. Positive correlation was observed between IST and TIR (r = 0.62, p < 0.01). Negative correlation was observed between IST and time below range (TBR) (r = − 0.40, p = 0.02), and IST and time above range (TAR) (r = − 0.45, p = 0.01). Total daily insulin dose was adequately increased without increasing hypoglycemia. There was only one heavy-for-date HFD) infant among the 11 newborns in SAP with PLGS cases. In cases without SAP (n = 11), target glycemic levels were difficult to achieve and there were 5 HFD infants among the 11 newborns. Conclusion: SAP with PLGS was safely and effectively used in pregnant women with type 1 diabetes to achieve target glucose levels without increasing the risk of hypoglycemia, which may have led to good neonatal outcomes.

Background: The relationship between inflammatory response, fish consumption, and mortality risk in older individuals is unclear. We investigated whether C-reactive protein (CRP) levels ≥ 0.1 mg/dL, fish intake, and inflammatory responses are associated with all-cause mortality risk in older adults. Methods: This prospective cohort study included older adults aged 85–89 years from the Kawasaki Aging and Wellbeing Project, who did not require daily care. Cohort was recruited from March 2017 to December 2018 (follow-up ended on December 31, 2021). Dietary assessment was conducted using the Brief Self-Administered Diet History Questionnaire. Multivariate Cox proportional hazards regression was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for all-cause mortality in the CRP ≥ 0.1 mg/dL group; the CRP < 0.1 mg/dL group was used for reference. Within CRP ≥ 0.1 and < 0.1 mg/dL groups, participants were categorized into tertiles of fish intake. HRs and 95% CIs for all-cause mortality in the other groups were estimated using the lower tertile group as a reference. Results: The study included 996 participants (mean [standard deviation] age, 86.5 [1.37] years; 497 [49.9%] women) with a median CRP level of 0.08 (interquartile range [IQR] = 0.04–0.16). There were 162 deaths during 4,161 person-years of observation; the multivariable-adjusted HR for all-cause mortality in the CRP ≥ 0.1 mg/dL group was 1.86 (95% CI, 1.32–2.62); P < 0.001. In 577 individuals with median (IQR) fish intake of 39.3 g/1000 kcal (23.6–57.6) and CRP level of < 0.1 mg/dL, the multivariable-adjusted HR for all-cause mortality in the higher tertile group of fish intake was 1.15 (0.67–1.97); P = 0.59, non-linear P = 0.84. In 419 individuals with median (IQR) fish intake of 40.7 g/1000 kcal (25.0–60.1) and CRP level of ≥ 0.1 mg/dL, the multivariate-adjusted HR for all-cause mortality in the higher tertile group of fish intake was 0.49 (0.26–0.92); P = 0.026, non-linear P = 0.38, P-value for interaction = 0.040. Conclusions: A negative association between fish intake and all-cause mortality was seen in older adults with elevated CRP levels, which is a mortality risk factor. While the results may be limited owing to stringent methods ensuring impartiality, they offer valuable insights for future research. Trial registration: UMIN000026053. Registered February 24, 2017.

Background: Increased protein intake has been recommended to prevent sarcopenia/frailty, reports on the quantity and quality of protein intake needed and the associated prognosis, particularly in the aging population of Asia, are limited. In this study, we aimed to investigate the relationship between protein intake and mortality in Japanese individuals, aged 85 years and older. Methods: The data were obtained from The Kawasaki Aging and Wellbeing Project, which is a prospective cohort study of older adults aged between 85 and 89 years with no physical disability at baseline. Of the 1,026 adults in the cohort, 833 were included in the analysis, after excluding those who had not completed a brief, self-administered diet history questionnaire or those who scored less than 24 on the Mini-Mental State Examination. The participants were grouped into quartiles based on protein intake: Q1 (protein < 14.7, %Energy), Q2 (14.7 ≤ protein < 16.7, %Energy), Q3 (16.7 ≤ protein < 19.1, %Energy), and Q4 (≥ 19.1, %Energy). Multivariate Cox proportional hazards models were utilized to evaluate the association between protein intake and all-cause mortality. Kaplan–Meier survival curves were employed to investigate the relationship between protein intake and all-cause mortality. Results: The mean protein intake of our study population was 17.0% of total energy. Animal protein intake, particularly fish intake, increased significantly along with total protein intake. The study had an average observation period of 1,218 days and recorded 89 deaths. After adjusting for age, sex, skeletal muscle mass index, cardiovascular disease, cancer, education, and serum albumin levels, a lower risk of all-cause mortality was observed in the highest protein intake (Q4) group than in the lowest protein intake (Q1) group (hazard ratio: 0.44, 95% confidence interval: 0.22–0.90, p-value: 0.020). Conclusion: Protein intake is associated with a reduced risk of all-cause mortality in older adults (aged ≥ 85 years) who engage in independent activities of daily living. This association may impact all-cause mortality independent of muscle mass.

Background and aims: To investigate the association between the frequency of intermittent-scanning continuous glucose monitoring (isCGM) and diurnal variation of time in range (TIR), time above range (TAR), and time below range (TBR), we performed a post hoc analysis of the ISCHIA study, a multicenter, prospective, open-label, randomized crossover study of patients with type 1 diabetes mellitus. Method: Data of 93 people who completed the ISCHIA study were used. We calculated scan frequency, TAR, TIR, and TBR of four approximately 6-h intervals: 6:00–11:59 (morning), 12:00–17:59 (afternoon), 18:00–23:59 (evening), and 0:00–5:59 (night). The correlation between scan frequency and diurnal variation of CGM metrics was analyzed using nonparametric Spearman correlation analysis. Results: More frequent scanning was associated with higher TIR in the afternoon (rho = 0.343, P < 0.001), evening (rho = 0.243, P = 0.019), and night (rho = 0.218, P = 0.036); furthermore, it was associated with lower TAR in the afternoon (rho = -0.275, P = 0.008) and TBR in the evening (rho = -0.235, P = 0.024). Concern about the effect of blood glucose fluctuation on social communication affected the number of scans during the day. Concerns about loneliness and hypoglycemia when alone also influenced the number of nighttime scans. Conclusion: Scan frequency is influenced by psychological factors. Afternoon scans were associated with the highest increase in TIR and decrease in TAR. Evening scans were linked to a reduction in TBR.

Background: Obesity is increasingly being recognized as a chronic disease that exacerbates type 2 diabetes and its related complications. Oral semaglutide, a novel glucagon-like peptide-1 (GLP-1) receptor agonist, has demonstrated efficacy in weight loss and diabetes control in Western populations. However, in real-world clinical practice, its effectiveness in Japanese patients, who typically exhibit a leaner phenotype and unique genetic susceptibilities affecting insulin secretion, remains unclear. Methods: We retrospectively evaluated the electronic medical records of 313 patients treated with oral semaglutide and 11,239 untreated controls at the Keio University School of Medicine. We performed propensity score matching to adjust for covariates, including age, sex, height, weight, blood pressure, blood test data, medications, and compared the cardiometabolic risk factors, including HbA1c, blood pressure, lipids, and liver function 180 days post-treatment, of both patient groups. We conducted a subgroup analysis for patients who achieved ≥ 3% weight loss. Results: After propensity score matching, the semaglutide group demonstrated significantly better outcomes for HbA1c reduction and weight loss and improvements in systolic blood pressure (SBP), low-density lipoprotein cholesterol (LDL-C), and liver function than the control group. Subgroup analysis of patients with ≥ 3% weight loss revealed superior HbA1c improvements in the semaglutide group; however, no significant differences in other metabolic parameters, such as SBP, LDL-C, and liver function, were observed. Conclusion: Oral semaglutide effectively improved metabolic markers in Japanese patients with type 2 diabetes, similar to that in Western populations. Weight loss itself was suggested to significantly contribute to blood pressure, lipid levels, and liver function changes.

Background: Strict glycemic control is important to prevent perinatal complications in patients with gestational diabetes mellitus (GDM). Patients often require insulin injection, and frequent hospital visits are necessary to adjust the dose of insulin, which is considered burdensome for pregnant patients. Telemedicine may reduce the burden of hospital visits, and previous studies have reported its safety in GDM patients. This study aimed to evaluate the efficacy of telemedicine in GDM patients, focusing on patient satisfaction and health economic indicators. Methods: This is a single-center, two-arm, randomized, open-label parallel-group study. Subjects will be selected from the patient population attending the Department of Endocrinology, Metabolism, and Nephrology, Keio University School of Medicine, Japan. Patients diagnosed with GDM by an oral glucose tolerance test (OGTT) by 29 weeks and 6 days of gestation who have undergone self-monitoring of blood glucose (SMBG) and insulin injection are eligible for inclusion. In the intervention group, telemedicine will be administered using the MeDaCa telemedicine system developed by the Medical Data Card, Inc., Tokyo, Japan. Subjects in the control group will be examined face-to-face every 2–3 weeks, as usual. We set health economic indicators and patient satisfaction as the primary endpoints, and will perform a cost-consequence analysis. Glycemic control indicators and perinatal outcomes will be evaluated as secondary endpoints. Conclusions: Eligible patients are currently being recruited. Recruitment will be completed when the expected number of patients are enrolled.

The study was aimed to investigate the seasonal variation of hemoglobin A1c (HbA1c) in adults with type 1 diabetes (T1D) and the impact of coronavirus disease 2019 (COVID-19) by comparing 2019 and 2021 data and differences in treatment modes. This was a single-center retrospective observational study including 52 adult patients with T1D who regularly visited hospital in 2019 and 2021. Twenty-five patients used multiple daily injections (MDI)/self-measurement of blood glucose (SMBG), 16 used MDI/intermittently scanned continuous glucose monitoring (isCGM), 9 used sensor-augmented pump (SAP), and 2 used continuous subcutaneous insulin infusion (CSII)/isCGM. The mean HbA1c level was calculated for each month. The correlation between monthly means of temperature and HbA1c was investigated. Similar analyses were performed for the MDI/SMBG, MDI/isCGM, and SAP + CSII/isCGM groups. HbA1c levels in 2019 decreased in summer and increased in winter and showed a significant negative correlation with temperature (r = –0.652, p = 0.022). However, HbA1c in 2021 showed no seasonal variation and no correlation with temperature (r = –0.134, p = 0.678) and tended to decline after the three emergency declarations. HbA1c in the MDI/SMBG group showed the same trend as the whole group in 2019 and 2021. However, the effect of seasonal variation in HbA1c was lower in the MDI/isCGM group and the lowest in the SAP + CSII/isCGM group in 2019. The impact of emergency declaration on HbA1c level was small for the MDI/isCGM group and smaller for the SAP + CSII/isCGM group in 2021. The COVID-19 pandemic has affected the seasonal variation of HbA1c levels in T1D; the variation differed according to the treatment mode.

The vaccine for the coronavirus disease 2019 (COVID-19) has been reported to potentially cause or worsen diabetes. A 73-year-old Japanese woman received two doses of Moderna COVID-19 vaccine. Four weeks after the second vaccination, her glycemic control began to deteriorate, and 8 weeks after the second vaccination, the patient was diagnosed with new-onset type 1 diabetes that was strongly positive for autoantibodies and showed a disease-susceptible human leukocyte antigen haplotype, DRB1*04:05:01-DQB1*04:01:01. The glucagon stimulation test suggested an insulin-dependent state, and induction of intensive insulin therapy brought about fair glycemic control. The time period from the COVID-19 vaccination to the development of type 1 diabetes was relatively longer than to the onset or exacerbation of type 2 diabetes, as previously reported, suggesting the complicated immunological mechanisms for the destruction of β-cells associated with the vaccination. In recipients with the disease-susceptible haplotypes, one should be cautious about autoimmune responses for several months after the vaccination.

Objective: We previously reported the mean average relative difference (MARD) of the sensor glucose (SG) of the first-generation FreeStyle Libre with the original algorithm, an intermittent scanning continuous glucose monitoring (isCGM) device, was 15.6% in the Effect of Intermittent-Scanning Continuous Glucose Monitori ng to Glycemic Control Includi ng Hypoglycemia and Quality of Life of Patients with Type 1 Diabetes Mellitus Study (ISCHIA Study). In the present study, we aimed to further analyze its accuracy in detail by conducting a post-hoc analysis of the study. Methods: The ISCHIA Study was a multicenter, randomized, cross-over trial to assess the efficacy of isCGM. The SG levels of isCGM and the measured capillary blood glucose (BG) levels of 91 participants were used for the analysis. Results: Bland-Altman analysis showed bias of-13.0 mg/dl when the SG levels were compared to the BG levels, however no proportional bias was observed (r = 0.085). MARD of the participants without and with contact dermatitis were 15.0 ± 6.0% and 27.4 ± 21.4% (P = 0.001), respectively. Conclusion: There was negative bias in the SG levels of isCGM compared to the BG levels. There is a possibility that the complication of the contact dermatitis during isCGM use may be related with deteriorated accuracy of the SG levels.

Aim: The Effect of Intermittent-Scanning Continuous Glucose Monitoring to Glycemic Control Including Hypoglycemia and Quality of Life of Patients with Type 1 Diabetes Mellitus (ISCHIA) study was a randomized, crossover trial that reported the decrease in time below range (TBR) by the use of intermittent-scanning continuous glucose monitoring (isCGM) combined with structured education in adults with type 1 diabetes (T1D) treated by multiple daily injections. The participants were instructed to perform frequent scanning of the isCGM sensor (10 times a day or more) and ingest sugar when impending hypoglycemia is suspected by tracking the sensor glucose levels and the trend arrow. We conducted post-hoc analysis to identify factors affecting difference in TBR (∆TBR), in time in range (∆TIR), and in time above range (∆TAR). Participants and methods: Data from 93 participants who completed the ISCHIA study were used. Multiple regression analyses were performed to identify factors affecting CGM metrics. Results: Pearson’s correlation analysis showed the negative association between log-transformed scan frequency and with ∆TBR (r = − 0.255, P = 0.015), while there was no significant association of log-transformed scan frequency with ∆TIR (r = 0.172, P = 0.102) and ∆TAR (r = 0.032, P = 0.761), respectively. The log-transformed scan frequency was an independent predictor of ∆TBR (Beta = − 7.712, P = 0.022), but not of ∆TIR(Beta = 7.203, P = 0.091) and of ∆TAR (Beta = 0.514, P = 0.925). Conclusions: Our findings suggest that more frequent scanning of isCGM may be beneficial to reduce TBR in T1D adults.

© 2019 The Authors Aims: To evaluate the efficacy and safety of switching to insulin glargine 300 U/mL (Gla-300) from insulin glargine 100 U/mL (Gla-100) in Japanese patients with type 2 diabetes (T2DM). Methods: This was a 12-month retrospective study comprising 109 patients. Primary endpoint was glycated hemoglobin (HbA1c) level at month 12. Secondary endpoints were hypoglycemia for the overall study period as well as body weight and insulin dose at month 12. Results: Similar glycemic control was achieved with mean (standard deviation) HbA1c level of 7.7 (1.1)% (61 [12] mmol/mol) at baseline and 7.7 (1.3)% (61 [14] mmol/mol) at month 12. Fewer confirmed (<3.0 mmol/L [< 54 mg/dL]) or severe hypoglycemic events were observed (0.52 vs. 0.85 events per patient-year; rate ratio 0.61; 95% confidence interval 0.38–0.97; p = 0.037), but the percent of patients experiencing ≥1 hypoglycemic event did not differ. There was no difference in confirmed (≤3.9 mmol/L [≤ 70 mg/dL]) or severe hypoglycemia and nocturnal hypoglycemia. Conclusions: In Japanese patients with T2DM who switched to Gla-300 from Gla-100, similar glycemic control was achieved with fewer confirmed (<3.0 mmol/L [< 54 mg/dL]) or severe hypoglycemic events over a 12-month period, although the absolute benefit was marginal.

Aims/Introduction: To evaluate the efficacy and safety of once-weekly (q.w.) extended-release exenatide after switching from twice-daily (b.i.d.) exenatide in patients with type 2 diabetes. Materials and Methods: This was an investigator-initiated, prospective, single-arm, multicenter study. Individuals with type 2 diabetes who had been treated with exenatide b.i.d. for at least 3 months were enrolled and switched to exenatide q.w. for 24 weeks. The primary end-point was change in HbA1c at week 24 to test the glucose-lowering effect of exenatide q.w. versus exenatide b.i.d. Results: A total of 58 Japanese individuals with type 2 diabetes completed the study. Glycated hemoglobin was reduced by 0.2% at week 24 (7.2 ± 1.2% vs 7.0 ± 1.2% [56 ± 13 vs 53 ± 13 mmol/mol], 95% confidence interval −0.4 to −0.03%, P < 0.005 for non-inferiority, P = 0.01 for superiority). Fasting plasma glucose was reduced by 12 mg/dL at week 24 (154 ± 46 vs 142 ± 46 mg/dL, P = 0.02). β-Cell function assessed by homeostasis model assessment of β-cell function and C-peptide index was significantly improved at week 24. The incidence of self-reported hypoglycemia was reduced, and treatment satisfaction assessed by the Diabetes Treatment Satisfaction Questionnaire and Diabetes Medication Satisfaction Questionnaire was improved at week 24, with no change in body weight. There was no serious adverse event related to the study drug. Conclusions: Switching from exenatide b.i.d. to exenatide q.w. resulted in a reduction in glycated hemoglobin, fasting plasma glucose and the incidence of hypoglycemia, and improvement in β-cell function and treatment satisfaction in patients with type 2 diabetes. These findings will be useful for selecting optimal treatment in individuals with type 2 diabetes.

Aims/Introduction: As estimated glomerular filtration rate (eGFR) progression might correlate with cardiovascular prognosis, the correlation between 1-year decline in eGFR and cardiovascular incidences and renal outcome was investigated. Materials and Methods: The 1-year percentage decline in eGFR at the first observation year was calculated in a cohort of the standard versus intEnsive statin therapy for hypercholesteroleMic Patients with diAbetic retinopaTHY (EMPATHY) trial participants. The primary end-point was the composite cardiovascular end-point including the renal end-point. The associations between the incidence of each end-point and clinical markers were analyzed using the Cox proportional hazards regression model. Results: A total of 4,461 patients were analyzed. The mean observation period was 765.3 ± 363.1 days. The best cut-off value of 1-year eGFR decline was 0.099 in the first year for renal end-point prediction by receiver operating characteristic curve analysis. The area under the curve of the model including the 1-year eGFR decline of the first year was significantly larger than the model without it (0.943, 95% confidence interval 0.915–0.971 to 0.967, 95% confidence interval 0.950–0.983, P = 0.019). Primary end-point incidences and the renal end-point were much higher in rapid eGFR decliners compared with non-decliners (P < 0.0001). The cardiovascular end-point incidence, except for the renal end-point, was not different between the groups. According to Cox regression analysis, 1-year eGFR decline during the first year was a significant risk factor for the end-points, including the renal end-point, independent of albuminuria and eGFR at baseline. Conclusions: The 1-year eGFR decline rate provided useful information for cardiovascular end-point predictions, including the renal end-point, in addition to the conventional risk factors.

Glucocorticoid causes hyperglycemia, which is common in patients with or without diabetes. Prolonged hyperglycemia can be experienced even after the discontinuation of glucocorticoid use. In the present study, we examined the time course of blood glucose level in hospital patients who received transient glucocorticoid treatment. In addition, the mechanism of prolonged hyperglycemia was investigated by using dexamethasone (Dexa)-treated mice and cultured cells. The blood glucose level in glucose tolerance tests, level of insulin and glucagon-like peptide 1 (GLP-1), and the activity of dipeptidyl peptidase 4 (DPP-4) were examined during and after Dexa loading in mice, with histone acetylation level of the promoter region. Mice showed prolonged hyperglycemia during and after transient Dexa loading accompanied by persistently lower blood GLP-1 level and higher activity of DPP-4. The expression level of Dpp-4 was increased in the mononuclear cells and the promoter region of Dpp-4 was hyperacetylated during and after the transient Dexa treatment. In vitro experiments also indicated development of histone hyperacetylation in the Dpp-4 promoter region during and after Dexa treatment. The upregulation of Dpp-4 in cultured cells was significantly inhibited by a histone acetyltransferase inhibitor. Moreover, the histone hyperacetylation induced by Dexa was reversible by treatment with a sirtuin histone deacetylase activator, nicotinamide mononucleotide. We identified persistent reduction in blood GLP-1 level with hyperglycemia during and after Dexa treatment in mice, associated with histone hyperacetylation of promoter region of Dpp-4. The results unveil a novel mechanism of glucocorticoid-induced hyperglycemia, and suggest therapeutic intervention through epigenetic modification of Dpp-4.

Objective: To examine patient preference for treatment with the oral once-weekly dipeptidyl peptidase-4 inhibitor (DPP-4i), trelagliptin, and oral once-daily DPP-4i, alogliptin, administered for 8 weeks each in patients with type 2 diabetes mellitus prescribed a daily DPP-4i. Methods: In this randomized, open-label, two-way crossover study, patients received trelagliptin followed by alogliptin (T-A group) or alogliptin followed by trelagliptin (A-T group), for 8 weeks each (NCT03231709, JapicCTI-173662). Treatment preference was assessed using a standardized questionnaire in the overall population and by baseline characteristics. Other outcomes included patient satisfaction with diabetes treatment (assessed using the Diabetes Treatment Satisfaction Questionnaire [DTSQ]), hemoglobin A1c (HbA1c) levels after 8 weeks of treatment with each agent, and safety. Results: Sixty patients from two clinical sites were randomized 1:1 to T-A and A-T groups (each n = 30); baseline characteristics were similar between groups. After 16 weeks of treatment, 51.7% of patients preferred treatment with alogliptin compared with 30.0% selecting trelagliptin (p =.014); preference for alogliptin was consistently greater than for trelagliptin in the secondary analyses by baseline characteristics. DTSQ score and HbA1c levels were similar between treatments after 8 weeks of therapy. Both treatments demonstrated favorable safety and tolerability profiles. Conclusions: Patients expressed a significantly greater treatment preference for once-daily alogliptin than once-weekly trelagliptin, although patient satisfaction and HbA1c levels were similar across treatments. The decision to administer a once-weekly or once-daily DPP-4i is likely to depend on patient preference, patient-physician discussions, and treatment practices of the prescribing physician.

© The Author(s) 2018. Background: Glycated albumin reflects 2–3-week glycaemic controls, and in addition to glycated haemoglobin, it has been used as a glycaemic control indicator. We presumed that glycated albumin also has seasonal variations and is related to temperature, similar to glycated haemoglobin. Methods: The subjects were diabetic outpatients from April 2007 to March 2013. This resulted in the enrolment of 2246 subjects and the collection of a total of 53,968 measurements. Mean glycated haemoglobin, glycated albumin, and plasma glucose were calculated for each month over six years. The associations of the measures with each other and the average temperature for each month in Tokyo were assessed using Spearman rank correlation coefficients. Results: Plasma glucose was highest in January and lowest in May. Glycated haemoglobin was highest in March and lowest in September. Glycated albumin was highest in May and lowest in December. Glycated albumin tended to have a disjunction with plasma glucose in winter. Glycated haemoglobin had seasonal variation, but glycated albumin did not. Plasma glucose and glycated haemoglobin showed significant negative correlations with temperature (rs = −0.359, P < 0.001, rs = −0.449, P < 0.001, respectively), but glycated albumin did not. However, glycated albumin was inter-correlated with plasma glucose (rs = 0.396, P < 0.001) and glycated haemoglobin (rs = 0.685, P < 0.001), and glycated haemoglobin was inter-correlated with plasma glucose (rs = 0.465, P < 0.001). Conclusion: Glycated albumin and glycated haemoglobin showed different seasonal variations from each other over the six-year study period. Thus, further studies to identify factors that contribute to glycated albumin are needed.

Objective: The aim of this study was to clarify the association of maternal factors with perinatal complications in pregnancies complicated with type 1 (T1D) or type 2 diabetes (T2D). Methods: We conducted a retrospective chart review and enrolled 26 Japanese pregnant women with diabetes who received perinatal care at our hospital between 2008 and 2015. Perinatal complications were defined as one or more of the following: miscarriage, fetal death, fetal dysfunction, fetal structural anomaly, small-for-gestational age, large-for-gestational age (LGA), premature birth, neonatal hypoglycemia, pregnancy-induced hypertension (PIH), deterioration of maternal kidney function, and urgent Caesarean section (CS). The associations between perinatal complications and maternal factors were examined. Results: Approximately 70% and 50% of women with T1D and T2D experienced perinatal complications, respectively. LGA, neonatal hypoglycemia, and urgent CS were major perinatal complications in women with T1D, while PIH and urgent CS were major complications in those with T2D. In women with T1D, pre-gestational HbA1c was significantly higher in women with perinatal complications than in those without. In women with T2D, pre-gestational body mass index was significantly higher in women with perinatal complications than in those without. Conclusions: These findings suggest that while pre-gestational glycemic control remains the most important issue in women with T1D, pre-gestational weight control in addition to glycemic control should be greater emphasized in women with T2D to reduce the risk of perinatal complications.