Energy restriction combined with dipeptidyl peptidase-4 inhibitor exerts neuroprotection in obese male rats.

Dipeptidyl peptidase-4 (DDP-4) inhibitors and energy restriction (ER) are widely used to treat insulin resistance and type 2 diabetes mellitus. However, the effects of ER or the combination with vildagliptin on brain insulin sensitivity, brain mitochondrial function, hippocampal synaptic plasticity and cognitive function in obese insulin-resistant rats have never been investigated. We hypothesised that ER with DDP-4 inhibitor exerts better efficacy than ER alone in improving cognition in obese insulin-resistant male rats by restoring brain insulin sensitivity, brain mitochondrial function and hippocampal synaptic plasticity. A total of twenty-four male Wistar rats were divided into two groups and fed either a normal diet or a high-fat diet (HFD) for 12 weeks. At week 13, the HFD rats were divided into three subgroups (n 6/subgroup) to receive one of the following treatments: vehicle, ER (60 % of energy received during the previous 12 weeks) or ER plus vildagliptin (3 mg/kg per d, p.o.) for 4 weeks. At the end of the treatment, cognitive function, metabolic parameters, brain insulin sensitivity, hippocampal synaptic plasticity and brain mitochondrial function were determined. We found that HFD-fed rats demonstrated weight gain with peripheral insulin resistance, dyslipidaemia, oxidative stress, brain insulin resistance, impaired brain mitochondrial function and cognitive dysfunction. Although HFD-fed rats treated with ER and ER plus vildagliptin showed restored peripheral insulin sensitivity and improved lipid profiles, only ER plus vildagliptin rats had restored brain insulin sensitivity, brain mitochondrial function, hippocampal synaptic plasticity and cognitive function. These findings suggest that only a combination of ER with DPP-4 inhibitor provides neuroprotective effects in obese insulin-resistant male rats.

Effective ECG reference ranges for Northern Thai people.

BACKGROUND: The numerical values and ranges of the ECG are used as criteria for classifying types of arrhythmia. However, one criterion cannot be generically applied for all patient groups. Several studies have shown that age, gender, and race are the major key factors which produce variations in ECG values. METHODS: From May 2013 to February 2014, we collected 12 993 normal ECG data from 9853 Northern Thai patients at Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand, to analyse their ECG reference ranges. RESULTS: The results showed that the average heart rate decreased, while the PR interval and QTcB increased with increasing age in both genders. The normal range of heart rate was lower than the standard interval. QRS duration was stable in all age groups but longer in males than females. QRS axis deviated to the left with increasing age. SV1+RV5 amplitude slightly changed in both genders, but the upper limit crossed over the criteria of ventricular hypertrophy. CONCLUSIONS: We observed that the general trend of data was mainly similar to that found in other studies in Chinese, American, and African populations. However, some minor differences should be considered specifically for the Northern Thai population. Flexible criteria on conditions depending on age and gender should be adjusted for Northern Thai patients according to the results of this research.