Comparison of renal prognosis between dipeptidyl peptidase-4 inhibitor users and non-users.

AIM: To evaluate the renal prognosis of dipeptidyl peptidase-4 inhibitor (DPP-4i) users and non-users using real-world Asian data. METHODS: Using databases from DeSC Healthcare, Inc., patients aged 30 years or older who used antidiabetic drugs from 2014 to 2021 were identified. Propensity score matching analyses were used to compare renal prognosis between DPP-4i users and non-users. The primary outcomes were estimated glomerular filtration rate (eGFR) decline and end-stage kidney disease (ESKD) development in the eGFR of 45 mL/min/1.73m2 or higher and eGFR of less than 45 mL/min/1.73m2 groups, respectively. RESULTS: In total, 65 375 and 9866 patients were identified in the eGFR of 45 mL/min/1.73m2 or higher and eGFR of less than 45 mL/min/1.73m2 groups, respectively. In the eGFR of 45 mL/min/1.73m2 or higher group, propensity score matching created 16 002 pairs. A significant difference was observed in the primary outcome of eGFR decline between DPP-4i users and non-users at 2 years (-2.31 vs. -2.56 mL/min/1.73m2: difference, 0.25 mL/min/1.73m2; 95% confidence interval [CI], 0.06-0.44) and 3 years (-2.75 vs. -3.41 mL/min/1.73m2: difference, 0.66 mL/min/1.73m2; 95% CI, 0.39-0.93). In the eGFR less than 45 mL/min/1.73m2 group, propensity score matching created 2086 pairs. After a mean of 2.2 years of observation, ESKD development was 1.15% and 2.30% in users and non-users, respectively, and Kaplan-Meier analysis revealed a significant difference (log rank P = .005). CONCLUSIONS: This retrospective real-world study revealed that patients using DPP-4is had a better renal prognosis than those not using DPP-4is.

Usefulness and caveats of real-world data for research on hypertension and its association with cardiovascular or renal disease in Japan.

The role of real-world data, collected from clinical practice rather than clinical trials, has become increasingly important for investigating real-life situations, such as treatment effects. In Japan, evidence on hypertension, cardiovascular diseases, and kidney diseases using real-world data is increasing. These studies are mainly based on "the insurer-based real-world data" collected as electronic records, including data from health check-ups and medical claims such as JMDC database, DeSC database, the Japan Health Insurance Association (JHIA) database, or National Databases of Health Insurance Claims and Specific Health Checkups (NDB). Based on the insurer-based real-world data, traditional but finely stratified associations between hypertension and cardiovascular or kidney diseases can be explored. The insurer-based real-world data are also useful for pharmacoepidemiological studies that capture the distribution and trends of drug prescriptions; combined with annual health check-up data, the effectiveness of drugs can also be examined. Despite the usefulness of insurer-based real-world data collected as electronic records from a wide range of populations, we must be cautious about several points, including issues regarding population uncertainty, the validity of cardiovascular outcomes, the accuracy of blood pressure, traceability, and biases, such as indication and immortal biases. While a large sample size is considered a strength of real-world data, we must keep in mind that it does not overcome the problem of systematic error. This review discusses the usefulness and pitfalls of insurer-based real-world data in Japan through recent examples of Japanese research on hypertension and its association with cardiovascular or kidney disease.

Combined effects of blood pressure and glucose status on the risk of chronic kidney disease.

This study aimed to assess the combined effects of blood pressure (BP) and glucose status on chronic kidney disease (CKD) incidence in young and middle-aged adults. We examined data from 1,297,341 Japanese individuals aged <60 years (60.1% men; mean age 41.4 ± 9.3 years) with no history of CKD at baseline. The interval-censored Cox proportional hazards model with covariates was used. During a median follow-up period of 2.1 years, new onset CKD (estimated glomerular filtration rate <60 ml/min/1.73 m2 and/or proteinuria) occurred in 80,187 participants. In participants without antihypertensive treatment (AHT), the adjusted hazard ratios (95% confidence interval) per 1-standard deviation, that is, 15 mmHg increase in systolic BP for CKD incidence, were 1.08 (1.07-1.09), 1.12 (1.10-1.13), and 1.15 (1.12-1.18) in normoglycemia, borderline glycemia, and diabetes groups, respectively. These ratios were significantly higher in the borderline glycemia and diabetes groups compared with those in the normoglycemia group (interaction p < 0.0001). The interaction between BP and borderline glycemia was evident when the outcome definition was restricted to proteinuria. In participants under AHT, systolic BP was most strongly associated with CKD risk in the diabetes group, although no significant interaction was observed. High BP and high glucose status may synergistically increase the incidence of CKD. Strict BP management may play an important role in the early prevention of CKD in individuals with worse glucose status within the young and middle-aged population. This large-scale longitudinal cohort study showed high BP and diabetes synergistically increased the risk of CKD in individuals without AHT. Strict BP management may play an important role in the early prevention of CKD in individuals with worse glucose status within the young and middle-aged population.

Cross-classification by systolic and diastolic blood pressure levels and chronic kidney disease, proteinuria, or kidney function decline.

Predicting and preventing new-onset chronic kidney disease (CKD) through blood pressure (BP) measurements is worthwhile. This study assessed the risk of CKD, which was defined as proteinuria and/or an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2, according to cross-classification by systolic and diastolic BP (SBP and DBP). This retrospective population-based cohort study analyzed data from 1,492,291 participants without CKD and without antihypertensive treatment in the JMDC database, which contains the annual health check-up data of Japanese aged <75 years. During a mean follow-up of 3.2 years, CKD incidence, proteinuria, and eGFR <60 mL/min/1.73 m2 occurred in 92,587, 67,021, and 28,858 participants, respectively. When the SBP/DBP <120/<80 mmHg group was set as a reference, both high SBP and DBP were significantly associated with an elevated CKD risk. DBP tended to be more strongly associated with CKD risk than SBP; the hazard ratio of CKD was 1.44-1.80 in the group with SBP/DBP of 130-139/≥90 mmHg and 1.23-1.47 in the group with SBP/DBP of ≥140/80-89 mmHg. A similar result was observed for developing proteinuria and eGFR <60 mL/min/1.73 m2. SBP/DBP ≥150/<80 mmHg was strongly associated with an elevated CKD risk due to the increased risk of eGFR decline. High BP, especially isolated high DBP levels, is a significant risk factor for CKD among individuals around middle age without kidney disease. Moreover, attention should be paid to kidney function, particularly eGFR decline, in the case of low DBP with extremely high SBP levels.

A case of light chain (AL) amyloidosis with heart failure, renal dysfunction, and heparin-induced thrombocytopenia successfully treated with peritoneal dialysis.

A 65-year-old woman was hospitalized for heart failure and pneumonia in a nearby hospital. She had been previously diagnosed as light chain (AL) amyloidosis and treated with melphalan plus dexamethasone (Mel-Dex), and lenalidomide plus dexamethasone (Len-Dex). She started treatment including antimicrobials and diuretics, but her renal function worsened progressively, and she was transferred to our hospital for nephrological care. She was treated with antimicrobials, noradrenaline, dobutamine, and continuous hemodiafiltration. Her general condition gradually stabilized, and she was switched to intermittent hemodialysis (HD). However, HD was discontinued due to intradialytic hypotension and the development of heparin-induced thrombocytopenia. Her renal replacement therapy was switched to peritoneal dialysis (PD), which enabled good volume control and stable cardiac function. She was discharged and is still in good condition, without serious complications and achieving a considerably better prognosis than was predicted. Our case suggests that PD is an effective modality for patients with AL amyloidosis with heart failure and renal dysfunction.