Seasonal and diurnal variations in soil respiration rates at a treeline ecotone and a lower distribution limit of subalpine forests.

This study examined the seasonal and diurnal variations in soil respiration rates (RS) during a growing season at the treeline ecotone (2,800 m) and the lower distribution limit (1,600 m) of subalpine forests on a volcanic mountain in Japan. The aboveground biomass, the total RS during the growing season, and the RS per day during the growing season were lower at 2,800 m than those at 1,600 m. Seasonal RS variations positively correlated with those of soil and air temperatures at both elevations, and this tendency was more apparent at 1,600 m than 2,800 m. The mean volumetric soil water content (WS) during the growing season was much lower at 2,800 m than 1,600 m because of the scoria substrate at 2,800 m. The monthly mean diel cycle of RS was positively correlated with the soil temperature at each elevation every month, whereas that at 1,600 m was negatively correlated with that of the WS. The RS at 2,800 m decreased during the daytime especially in August, despite no changes in the WS. The decrease in RS after precipitation at 1,600 m was higher than that at 2,800 m. Seasonal and diurnal RS variations could be reproduced from soil and air temperatures, and WS. Estimating soil respiration rate from these variables will help understand the future carbon budget of forests due to global warming.

Comparison of the Effectiveness of Once-Daily Alogliptin/Metformin and Twice-Daily Anagliptin/Metformin Combination Tablet in a Randomized, Parallel-Group, Open-Label Trial in Japanese Patients with Type 2 Diabetes.

INTRODUCTION: The combination tablets of dipeptidyl peptidase-4 (DPP-4) inhibitors and metformin are used for both once-daily and twice-daily agents in Japan. If there is no difference in effectiveness between the once-daily and twice-daily DPP-4 inhibitor/metformin combination tablets, the once-daily agent is advantageous in terms of frequency of administration. The aim of this study was to compare the effectiveness of once-daily alogliptin/metformin combination tablet (alogliptin 25 mg/metformin 500 mg) and twice-daily anagliptin/metformin combination tablet low dose (LD) (anagliptin 100 mg/metformin 250 mg). METHODS: Forty-eight Japanese patients with type 2 diabetes whose metformin administration of 250 mg twice daily had remained unchanged for at least 8 weeks, except when using DPP-4 inhibitors, glucagon-like peptide-1 receptor agonists, or insulin, were randomized to either the once-daily alogliptin/metformin combination tablet group or the twice-daily anagliptin/metformin combination tablet LD group. The primary endpoint was the difference in glycosylated hemoglobin (HbA1c) levels from baseline to week 12 of administration, whereas the secondary endpoints were fasting blood glucose, body mass index (BMI), and adherence. RESULTS: Forty-four patients completed the study, and intention-to-treat analyses were performed. The adjusted mean value (standard error) for the change in HbA1c from week 0 to 12, was - 0.75 (0.109)% for the once-daily alogliptin/metformin combination tablet group and - 0.65 (0.109)% for the twice-daily anagliptin/metformin combination tablet LD group, with an intergroup difference of - 0.10% (95% confidence interval, CI - 0.407, 0.215). The upper limit of the bilateral 95% CI was 0.215%, below the 0.40% pre-defined as the non-inferiority margin. Fasting blood glucose, BMI, and adherence were not significantly different between the groups. CONCLUSIONS: The once-daily alogliptin/metformin combination tablet was non-inferior to the twice-daily anagliptin/metformin combination tablet LD in Japanese patients with type 2 diabetes. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trial Registry (UMIN-CTR) (registration number: UMIN000034951).

A case of an elderly patient with insulin-dependent diabetes and dementia receiving one basal insulin plus one bolus insulin injections a day for 6 months.

Multiple daily injections of insulin, referred to basal-bolus regimen, are generally essential in achieving glycemic control and preventing ketosis in insulin-dependent diabetes, such as type 1 diabetes (T1D). A 75-year-old man with T1D receiving basal-bolus insulin therapy exhibited symptoms of dementia after hospitalization due to pyelonephritis and failed to continue insulin self-injection. Given that his social and familial circumstances allowed insulin injection once a day during the morning, bolus insulin injections needed to be discontinued. Ketonuria was observed the day following discontinuation of bolus insulin. Although increasing the basal insulin dose (degludec) from 10 to 15 units improved ketonuria, his preprandial glucose levels increased to ≥ 500 mg/dL before lunch and ≥ 400 mg/dL before dinner. Hence, another bolus insulin injection was simultaneously added to the basal insulin dose before breakfast, which, subsequently, decreased his preprandial glucose levels to ≤ 220 mg/dL before lunch and ≤ 350 mg/dL before dinner. For half a year after discharge, ketonuria or hypoglycemia had not been detected. After 6 months, he was able to restart intensive insulin therapy with familial support. Hence, in cases where elderly patients with diabetes exhibit symptoms of dementia and can receive insulin injection once a day due to their social circumstances, short-term one basal plus one bolus insulin injections a day might be considered to prevent life-threatening diabetes complications among those who are insulin-dependent.