The Impact of Low-Volume High-Intensity Interval Training (LV-HIIT) on Fatty Liver Index (FLI) and Estimated Glomerular Filtration Rate (eGFR) in Patients with Type 2 Diabetes Mellitus (T2DM)

Raesi R, Kalbasi S, Gaeini AA, Ghasem Kashani MH, Tajik K

Question

What is the effect of a 4-week low-volume high-intensity interval training program on fatty liver index and estimated glomerular filtration rate in patients with type 2 diabetes?

Summary

In 80 sedentary adults with type 2 diabetes, a 4-week treadmill low-volume HIIT program was associated with reduced fatty liver index and increased estimated glomerular filtration rate compared with baseline, while the no-intervention control group did not improve eGFR. The intervention also improved several cardiometabolic markers, but the study was short and limited to one clinic population.

Methodology

Eighty sedentary adults aged 40-65 years with type 2 diabetes for at least one year and HbA1c 6.4%-10%, randomized to LV-HIIT or no-intervention control.
80 participants.
Treadmill interval exercise.
Work intervals: Four 1-min intervals at 70% HRmax.
Recovery: Three 4-min intervals at 60% HRmax between work intervals.
Intensity: 70% HRmax work intervals; 60% HRmax recovery intervals.
At least 21 min plus unreported warm-up duration.
3 sessions/week.
4 weeks.
Randomized controlled trial with two parallel groups: LV-HIIT and no-intervention control.
Fatty liver index, Estimated glomerular filtration rate, Fasting blood sugar and HbA1c, and Lipid profile were tracked.

Outcomes

Fatty liver index

FLI decreased within the LV-HIIT group from baseline to follow-up; post-intervention between-group FLI difference was not significant.

LV-HIIT 62.0 (30.0, 82.0) to 53.0 (22.5, 72.0), p<0.001 within group; post-intervention between-group p=0.623.

Improved

Estimated glomerular filtration rate

eGFR increased within the LV-HIIT group and was higher than control post-intervention.

LV-HIIT 71.0 (61.4, 76.7) to 73.6 (69.1, 76.1), p<0.001 within group; post-intervention between-group p=0.021.

Improved

Glycemic control

LV-HIIT reduced fasting blood sugar and HbA1c within group; post-intervention FBS was lower than control, while HbA1c between-group difference was not significant.

FBS 129.0 to 121.0, p<0.001 within LV-HIIT and post-intervention between-group p=0.014; HbA1c 7.0 to 6.5, p<0.001 within LV-HIIT and post-intervention between-group p=0.320.

Improved

Liver enzymes

ALT and GGT decreased within LV-HIIT and were lower than control post-intervention; AST did not significantly change.

ALT p<0.001 within LV-HIIT and p=0.041 between groups post-intervention; GGT p=0.012 within LV-HIIT and p=0.025 between groups; AST p=0.209 within LV-HIIT.

Improved

Anthropometrics and lipids

LV-HIIT reduced weight, BMI, waist circumference, LDL, triglycerides, and total cholesterol within group.

Weight, BMI, waist circumference, triglycerides, and total cholesterol p<0.001 within LV-HIIT; LDL p=0.001 within LV-HIIT.

Improved

Control group outcomes

Control group showed a significant reduction in fasting blood sugar and a significant worsening-direction change in FLI, with no significant eGFR change.

Control FBS p=0.002 within group; control FLI 51.0 to 52.5, p=0.001; control eGFR p=0.133.

Mixed

Insights

A short, 3-times-weekly interval program with 1-minute work bouts and longer low-intensity intervals may improve some surrogate metabolic, liver, and kidney markers in sedentary type 2 diabetes patients.
The protocol is only partly translatable because warm-up duration, achieved intensity, adherence, and adverse events were not reported.
For consumer use, claims should specify calculated FLI and estimated GFR rather than direct liver fat or kidney disease outcomes.

Limitations

Generalizability limited to patients referred to one diabetes clinic in Tehran, Iran.
No albuminuria marker of kidney disease.
Physical activity effects on muscle metabolism and creatinine production were not investigated.
Short 4-week study period.
Small sample size.
Adherence, dropout, achieved intensity, and adverse events were not reported.
Warm-up duration was not reported.

Safety

Participants completed health and sports history questionnaire and physician examination before randomization.
The study excluded people with functional limitations, respiratory, inflammatory, cardiovascular, renal, and other chronic diseases, smoking, or heavy drinking.
No adverse events, injuries, or dropout data were reported in the extracted article text.