Skin Temperature Gradient Effects on the Variation of Metabolic Hormones in Adults
Condition: Temperature Change, Body; Stress; Metabolic Disturbance
MeSH terms: Body Temperature Changes
Study type: Interventional

Summary: 
      The Cyprus International Institute for Environmental and Public Health of the Cyprus
      University of Technology is planning a pilot study of health indicators in relation to
      spatially varying climatic conditions ranging from the city to the mountainous environment.
      The purpose of the project is to understand the effect of fluctuations in external climatic
      conditions on the human body temperature and metabolic biomarkers or stress hormones.

      Climate change phenomena such as protracted heat waves that create areas with even higher
      temperatures, especially in urban centers, may have a negative impact on human health. The
      effects may be acute for an individual with the appearance of discomfort and headaches, while
      chronic exposures to high air temperatures for the general population have been linked with
      premature mortality and cardiovascular diseases. Due to climate change that is hitting hard
      the Mediterranean, these temperature changes have been more and more common in Cyprus in
      recent years.

      One of the usual ways of dealing with high temperatures is the use of air conditioners. With
      sudden and frequent temperature changes during the day, the human body is subject to thermal
      shock for varying duration and number of times, having wear and tear consequences for the
      human physiology. The investigators hypothesized that the number, duration and frequency of
      human exposures to wide gradient (> 8 ° C) of air temperature changes may be related to
      potential health problems. An intervention potentially reducing the health risk associated
      with extended exposure to high temperatures in the summer for Cypriots may be the temporary
      (for a few days or hours) stay in the villages of mountainous area. Most of the mountain
      communities in Cyprus have consistently lower mean ambient air temperatures of about 10
      degrees Celsius than those in the cities, so the investigators anticipate not observing the
      metabolic hormone alterations induced while being in the city environment.
    

Detailed description: 
      A randomised crossover trial study design was used to: investigate the circadian patterns of
      metabolic adipokines (leptin, adiponectin and ghrelin hormones), using targeted biomarker
      measurements and untargeted metabolomics in healthy adults residing in two different
      climatological environments: urban and higher in latitude mountainous settings, and ii)
      investigate the effect of skin temperature gradient on the variation of adipokines in the two
      settings (urban and rural).

      The study will take place in Cyprus. Participant recruitment will abide by the ethical
      principles and the guidelines of the National Bioethics Committee of Cyprus. Participants
      will be recruited after they read and complete the consent form and the whole study protocol
      is explained to them. Information about the study will be disseminated through flyers and
      through telephone communication via governmental and other non-profitable organizations that
      will contact community leaders of the area and help us collect and create a contact list of
      "Potential Participants". From there, potential participants will be informed about the study
      and screened for eligibility criteria via telephone.

      Upon consent, the "Potential Participants List" will have to be randomized to assign the
      participants in to two different groups. A total of 50-60 subjects will be followed for a
      period of one week firstly in an urban environment and later, for the same period, in a
      village of the mountainous rural environment, during the summer period in Cyprus.

      Once the researchers have names of potential participants, each name will be given a 2-digit
      code. This will be participant's study ID that will accompany participants answered
      questionnaires, diaries, urine vials and temperature measurement's files. The preparation of
      each tool with filled participants ID code and Date will be made at priory.

      There will be no blinding since the interventions are known to the participants and the
      researchers. There will be the necessary blinding during the conduct of the all laboratory
      and statistical analyses.

      The field workers and participants will arrange four visits. Visit 1 and 3 will take place
      one day before the sampling day which is the last day at each site(urban Vs rural), whereas
      visit 2 and 4 will take place a day after the sampling day when collection of the data will
      take place.

      Except the preparation for the first sampling day during the first visit, participants will
      be asked to sign the informed consent form and to fill in two survey questionnaires (baseline
      characteristics and chronotype questionnaire). During sampling days, participants will be
      handed with the diary of activities, urine vials for urine sample collection and the
      instructions form (for urine collection and the use of the personal temperature sensors).
      Electronic temperature sensors should be activated by the researchers on the spot and placed
      on the participant during the first and third visit. The temperature data collection will be
      ensured on the spot during the second and forth visit. Participants will be asked to collect
      urine voids by collecting all bladder content during urination in vials provided by the Water
      and Health Lab. The first urine void of each sampling day will be discarded. All urine voids
      for the rest of the sampling day, of each participant, will be collected, including the first
      urine void of the following day. Samples will be kept at a freezer by the participant until
      collected by a member of the research team, in cool boxes. Upon arrival at the Water and
      Health lab samples, aliquoting will take place and then aliquot samples will be stored in
      freezers of -80◦C, until analysis.

      Data collected will be digitized, anonymized and statistically evaluated. All data management
      steps will be employed to ensure that a final, clean, tidy and replicable dataset will be
      produced before proceeding to the statistical analysis. Descriptive statistics of the study
      population will be performed that will include parameters such as the mean and standard
      deviation for continuous variables and percentages for variables that indicate proportions.

      The effect of temperature gradient changes and hormonal level, as well as, differences in
      cortisol levels between and within subject variation will be examined. The statistical
      analyses will include a range of approaches from descriptive statistics to regression
      analysis and metabolomics analyses. Pre-post analyses, non-linear mixed effects models, will
      be used to identify correlations of the circadian rhythms of the participants between the two
      settings. Statistical evaluation and graphical presentation of results will be prepared for a
      final report and presentation. All statistical analyses will be conducted at the Water and
      Health laboratory.
    

Intervention name(s): Mountainous setting
Intervention type(s): Behavioral
Intervention description(s): The mountainous setting is characterized by lower temperatures (about 8-10C ambient air temp.) than those in urban setting, also having >800m altitude.Each period will last for 1 week with a wash out period of minimum 2 days. Continuous skin temperature and ambient temperature monitoring will take place in the last day of each period, towards the end. During the 2 sampling days, 24-hour urine voids will be collected in different vials. Participants will be required to fulfill a diary with their daily activities, meal times, collection of urine times, sleep/wake times and times of leaving/entering a closed environment.
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: A 2 x 2 cross-over pilot study of healthy adults is proposed to prospectively describe the effect of ambient temperature gradient on metabolic hormonal secretion patterns. A total of 50-60 subjects will be followed for a period of 7 days firstly in an urban environment or in a village of the mountainous rural environment and later, for the same period, in the alternate setting, during the summer period in Cyprus. The two settings will allow for the comparison of the circadian patterns of hormones secreted by the adipose tissue among different gradient temperature changes. Continuous quantification of skin temperatures on one day in each setting will allow for characterization of how skin temperature is affected by ambient temperature. Collection of all urine voids in one day in each setting will allow for quantification of the hormone secretion by the adipose tissue.
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Prevention