Core Temperature, Kidney Function Issue, Telomere Length, Mean Leukocyte
Conditions
Keywords
heat stress, heat strain, rickshaw, heart rate, heart rate variability, sleep quality, Bangladesh
Brief summary
The goal of the experimental study is to understand the impact of heat stress on core temperature and telomere length. Investigators will recruit rickshaw drivers who use manual power to push their rickshaws and randomly assign half of them to receive battery-powered rickshaws to use for four months. Investigators will assess how this change impacts their core body temperature while they work, the length of their telomeres (caps on the end of DNA that are associated with aging), and kidney function.
Detailed description
Personal exposure to heat may be elevated above ambient temperatures if an individual is very active (which generates metabolic heat) or wears clothing that prevents cooling. Age can influence the consequences of heat stress. Older adults are at elevated risk of adverse impacts from heat stress due to their reduced ability to dissipate heat. Heat stress is particularly high among outdoor workers. South Asia has millions of bicycle rickshaw drivers, who use their muscles or battery power to pull hundreds of pounds of passengers and goods on modified bicycles. When manual rickshaw drivers rest to cool off, they reduce their already meager income. Heat stress not only threatens their livelihoods and thereby their right to an adequate standard of living but also their right to work, given that they have few employable skills other than manual labor. South Asia faces the greatest current and predicted loss in disability-adjusted life years due to heat stress, and heat stress is particularly strong in informal settlements. As such, the investigators plan to conduct this study in Dhaka, Bangladesh. The overall hypothesis is that driving a battery-powered rickshaw will reduce heat strain. The investigators will evaluate the impact of driving a battery-powered rickshaw on core temperature (primary outcome), telomere length, kidney function, heart rate, heart rate variability, sleep quality, self-reported thermal comfort, mental health, wellness, and fatigue (secondary outcomes).
Interventions
DEVICEBattery-powered rickshaw
A battery-powered rickshaw is a rickshaw where the wheels are turned by a small electric motors powered by a battery.
Sponsors
International Centre for Diarrhoeal Disease Research, Bangladesh
North South University
University of California, Berkeley
Study design
Allocation
RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
SINGLE (Outcomes Assessor)
Intervention model description
Stepped-wedge randomized controlled trial
Eligibility
Sex/Gender
MALE
Age
40 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Reports driving a manual rickshaw at least five days per week for at least 8 hours per day for the past 12 months
Exclusion criteria
* Reports driving a battery-powered rickshaw in the past 12 months * Has hypertension, as measured by our study staff * Has diabetes, as measured by our staff * Reports diagnosis with cardiovascular disease / chronic cardiac condition * Reports diagnosis with respiratory disease / chronic respiratory condition
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Core temperature | 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention | Minutes per day that core temperature is \>40C, where fewer minutes per day is better |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Relative Leucocyte Telomere Length | 0 (pre-intervention) and 16 weeks post-intervention | Change in Relative Leucocyte Telomere Length measured by PCR, where a smaller reduction in length is better |
| Kidney function | 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention | kidney function, as measured by a the neutrophil gelatinase-associated lipocalin (NGAL) value in urine samples, where a lower score is better |
| Heart rate | 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention | resting heart rate (bpm), where a lower heart rate is better |
| Heart rate variability | 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention | resting heart rate (bpm) variability, where higher variability is better |
| Sleep quality | 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention | Self-reported sleep quality and number of minutes in REM, as recorded by a fitness watch, where more minutes in REM is better |
Contacts
Primary ContactLaura Kwong, PhD
Outcome results
None listed