Combined effects of vitamin D supplementation and endurance exercise training on insulin resistance in newly diagnosed type 2 diabetes mellitus patients with vitamin D deficiency: study protocol for a randomized controlled trial

Table 1 Summary of outcome measures

Outcomes	Item	Device
Primary outcomes
Insulin sensitivity and insulin secretion	The Matsuda index, the insulinogenic index, HOMA-IR, HOMA-β	OGTT
Insulin sensitivity and insulin secretion	The Matsuda index, the insulinogenic index, HOMA-IR, HOMA-β	Fasting blood measurements
Vitamin D level	Serum 25(OH)D, 1,25(OH)₂D	Fasting blood measurements
Secondary outcomes
Body composition	Percent body fat, muscle mass	DXA
Body composition	Waist circumference	Standard tape
Metabolic indices	Fasting glucose (G₀), fasting insulin (I₀), HbA1c, triglyceride, cholesterol, low-density lipoprotein, and high-density lipoprotein	Fasting blood measurements
Ankle-brachial index	Blood pressure, ABI, baPWV	Validated automatic device
Physical fitness factors	Peak oxygen uptake, maximal heart rate	Cycle ergometer
	Hand grip strength	Hand grip dynamometer

HOMA Homeostatic model assessment, IR Insulin resistance, 25(OH)D 25-hydroxyvitamin D, 1,25(OH)₂D 1,25-Dihydroxyvitamin D, OGTT Oral glucose tolerance test, DXA Dual-energy X-ray absorptiometry, HbA1c Glycated hemoglobin, ABI Ankle-brachial index

ISSN: 1745-6215