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CompletedNCT03408678Updated Jun 14, 2019

Determinants of Type 2 Diabetes Risk in Middle-aged Black South African Men and Women

An observational study in Diabetes Mellitus, Type 2, Insulin Resistance and Menopause, sponsored by University of Witwatersrand, South Africa. Completed at 1 site in South Africa. Open to participants aged 35 Years to 65 Years. Per ClinicalTrials.gov, last updated 2019-06-14.

Sponsored by University of Witwatersrand, South Africa · Observational

Study type
Observational
Model
Cohort
Time perspective
Retrospective
Enrollment
1,025
Ages
35 Years to 65 Years
Sex
All
01

Study summary

There is little known about menopause in African women, whose phenotype differs to Caucasian women, and no data is available on middle-aged black South African men. Accordingly, the study aims to examine the changes in sex hormone levels over the menopausal transition in women, and in men of the same age, and explore the effects on body fat distribution and insulin sensitivity and secretion, dissecting the specific roles of glucocorticoids and inflammatory mediators, in the context of HIV.

Research questions and hypotheses:

  1. Does the decrease in sex hormones that occur with ageing increase circulating cortisol and/or inflammatory markers, and directly and/or indirectly via increases in central fat mass, decrease insulin sensitivity in middle-aged black South African men and women?

    Hypothesis: The mechanism underlying the decrease in insulin sensitivity (outcome) associated with the decline in sex hormones (exposure) that occurs with ageing is mediated via an increase in centralization of body fat (mediator), which is due to an increase in inflammation and cortisol production.

  2. How does HIV alter the relationship between sex hormones, inflammation and cortisol levels, and subsequently body fat distribution and insulin sensitivity?

    Hypothesis: HIV infection will exacerbate the effects of the decline in sex hormones with ageing, leading to further increases in inflammation and cortisol production, and a consequent increase in the centralization of body fat and decrease in insulin sensitivity.

  3. Does adipose tissue glucocorticoid and inflammatory gene expression differ between pre- and post-menopausal women, with and without HIV, and how do these relate to body fat distribution and insulin sensitivity and secretion?

Hypothesis: Adipose tissue estrogen receptor beta (ERβ), 11-beta hydroxysteroid dehydrogenase type 1 (11HSD1) activity and pro-inflammatory markers will be higher in post- compared to pre-menopausal women, which will be exacerbated by HIV infection. This will be associated with down-regulation of subcutaneous adipose tissue (SAT) adipogenic genes, increased visceral adipose tissue (VAT), a decrease in insulin sensitivity and secretion, and consequently an increased risk for type 2 diabetes (T2D).

Read the detailed description

The study will be performed in two parts:

Part 1 - Using a longitudinal design, a sample of 500 black women at different stages of the menopausal transition, and 500 middle-aged men living in Soweto Johannesburg, South Africa, who were included in previous studies between 2011 and 2014, will be recruited. Socio-demographics, health and menopausal status will be assessed using questionnaires; physical activity and sedentary behaviour will be measured using accelerometry; dietary intake will be estimated using a food frequency questionnaire; body composition and body fat distribution will be assessed using dual energy x-ray absorptiometry (DXA); fasting blood samples will be drawn for the determination of cardio-metabolic risk (glucose, insulin, lipids), cluster of differentiation 4 (CD4) count, as well as sex hormones, inflammatory markers and cortisol concentrations. An oral glucose tolerance test will be performed to measure insulin sensitivity and secretion. Statistical analyses will include multilevel mediation modelling.

Part 2 - Using a cross-sectional design, a sub-sample of 100 women from Part 1 will be selected and divided into four groups including 25 pre-menopausal HIV-negative women and 25 age-matched pre-menopausal HIV-positive women (ARV-Naïve); 25 post-menopausal HIV-negative and 25 age-matched post-menopausal HIV-positive women (ARV-Naïve). The women will undergo a frequently sampled intravenous glucose tolerance test to measure insulin sensitivity and secretion, and adipose tissue biopsies will be taken from the gluteal and abdominal SAT depots for the analysis of gene and protein expression relating to inflammation, sex hormones, glucocorticoid metabolism and adipogenesis. Statistical analyses will include multilevel mediation modelling.

02

Conditions studied

  • Diabetes Mellitus, Type 2
  • Insulin Resistance
  • Menopause
  • Hiv

Keywords

  • body composition
  • glucocorticoids
  • inflammation
  • black African
  • sex
  • gonadal steroid hormones
03

Who can participate

Ages eligible
35 Years to 65 Years
Sexes eligible
All
Sampling method
Non-probability sample

Study population

A sample of 500 black women at different stages of the menopausal transition, and 500 middle-aged men living in Soweto Johannesburg, South Africa. The women are a sub-sample of 1007 women on whom baseline data was collected between 2011 and 2014 as part of the Study of Women Entering and in Endocrine Transition. The 500 women will be selected using a random process, to allow their profile to mirror that of the overall sample.

The men are a sub-sample of 962 black men on whom similar data was collected in 2014 as part of a larger African genomics study (www.h3africa.org). The 500 men will be randomly selected following the same approach applied to the female cohort.

Inclusion criteria

Part 1:

  • Women on whom baseline data was collected between 2011 and 2014 as part of the Study of Women Entering and in Endocrine Transition.
  • Men on whom baseline data was collected in 2014 as part of a larger African genomics study (www.h3Africa.org).

Part 2: A sub-sample of women from Part 1 of the study:

  • Pre-menopausal women age-matched within the age range 35-45 years;
  • Post-menopausal women age-matched within the age range 55-65 years;
  • All women: BMI 25-40 kg/m2

Exclusion criteria

Exclusion Criteria:

Part 1:

  • Failed to consent to participate in the study.

Part 2:

  • Diabetes, thyroid dysfunction, inflammatory, hepatic and renal diseases;
  • Use of hormone replacement therapy; hormonal contraceptives, oral cortisone, anti-inflammatory drugs or antiretroviral therapy;
  • Peri-menopausal;
  • Currently pregnant or lactating;
  • Tobacco use.
04

Study design

Observational model
Cohort
Time perspective
Retrospective
Enrollment
1,025 participants (actual)
Patient registry
No
Biospecimen retention
Samples with dna
05

What researchers measure

Primary outcomes

  1. Insulin sensitivity and secretion

    Part 1: insulin sensitivity and secretion estimated from an oral glucose tolerance test; Part 2: insulin sensitivity and secretion estimated using a frequently sampled intravenous glucose tolerance test

    Time frame: 4-6 years

Secondary outcomes

  1. Body fat distribution

    Body fat depots measured using dual energy x-ray absorptiometry

    Time frame: 4-6 years

06

Study locations

1 site
  • SAMRC/WITS Developmental Pathways of Health Research Unit, University of Witwatersrand
    Johannesburg, Gauteng 2013, South Africa
07

References and documents

Individual participant data

Plan to share: Yes — The principal investigators are prepared to share all individual patient data (IPD) with the wider scientific community, and will make the data available after all the results have been published.

Supporting information: Study protocol, Sap, Icf, Csr, Analytic code

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT03408678
Lead sponsor
University of Witwatersrand, South Africa
Collaborators
Medical Research Council, South Africa, GlaxoSmithKline, University of Oxford, University Hospital, Umeå
Responsible party
Julia Goedecke (Honorary Associate Professor, University of Witwatersrand, South Africa) — Principal investigator
First posted
Jan 24, 2018
Start date
Jan 23, 2017
Primary completion
Jul 31, 2018
Completion
Jul 31, 2018
Last update
Jun 14, 2019

Study contacts

Julia H Goedecke, PhD
principal investigator · Medical Research Council, South Africa
Lisa K Mickelsfield, PhD
principal investigator · University of Witwatersrand, South Africa

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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