Female Farm Workers At Higher Risk For The Metabolic Syndrome And Insulin Resistance, Western Cape Province, South Africa
Authors: Kruger Maritza J , Nell Theo A 
Published: November 2023

The prevalence of the metabolic syndrome (MetS), accompanied by insulin resistance (IR), is globally on the rise, and studies have shown that this is also true for the African, and South African settings. It was also established that the prevalence of the MetS is increased among farm workers in the United States, however no South African literature is available for this specific population. The aim was thus to describe the prevalence of the MetS and its association with IR in a farm worker population in the Boland district of the Western Cape, South Africa.

The study population consisted of 188 farm workers of both genders (n=147 females and n= 41 males) from the Stellenbosch and surrounding municipal areas in the Western Cape of South Africa. These farm workers were recruited as apparently healthy volunteers between the ages of 20 to 60 years. Using a cross‐sectional comparative study design, the males and females were divided according to their metabolic status by using the criteria formulated by the International Diabetes Federation (IDF). The four groups used for this specific study were: (1) MetS females, (2) non‐MetS females, (3) MetS males, and (4) non‐MetS males. Relevant demographic, anthropometric, and serum and plasma variables associated with the metabolic syndrome and insulin resistance were compared. To investigate possible relationships between different parameters of interest, Pearson correlations were also determined.

The overall prevalence of the MetS was 42.6 % (46.3 % for females and 29.3 % for males). Glucose was significantly higher in the MetS group compared to the non‐MetS group, but only for females (p<0.001). This difference was also evident for insulin (p<0.001). The quantitative insulin sensitivity check index (QUICKI) takes fasting insulin and glucose into consideration and is considered a useful and accurate measure of insulin sensitivity. This index revealed that both the non‐MetS males, as well as females had higher QUICKI indices compared to their MetS counterparts (p<0.01 for males and p<0.001 for females). Upon closer inspection, 60.1 % of the total population had a QUICKI index higher than 0.336, which is indicative of a possible risk to develop insulin resistance. Of these volunteers, 51.3 % and 26.5 % were females from the MetS and non‐MetS groups respectively. Very strong negative associations were evident between the QUICKI index and insulin in both the MetS (r=−0.70, p=0.000) and non‐Mets group (r=−0.80, p=0.00), irrespective of gender. Considering gender, very strong negative and significant correlations were evident for all four groups. Positive associations were also evident when glucose was correlated with insulin for all groups, however only the non‐Mets females showed a weak, but significant correlation (r=0.29, p=0.009).

This study revealed that the prevalence of the MetS is indeed high in a farm workers community of both genders in the Western Cape of South Africa, however, females seem to be more at risk. With specific regard to IR, which does not form part of the IDF's criteria for diagnosing an individual with the MetS, females again were shown to be more at risk for possible IR. Future studies should therefore not only focus on awareness of the risk factors associated with the MetS, but should also communicate the use of proper therapeutics or other nutritional or exercise interventions for the treatment of the MetS.

Support or Funding Information

This study was funded by the Cancer Association of South Africa (CANSA)