Contrasting impact of rural, versus urban, living on glucose metabolism and blood pressure in Uganda

Abstract

Background: The burden of cardiometabolic diseases, including cardiovascular diseases and diabetes, is increasing in sub-Saharan Africa and this has been linked to urbanisation. Helminths, through their immunomodulatory properties, may protect against these disorders. We hypothesised that the rural environment protects against cardiometabolic diseases and that helminths may influence rural-urban disparity of cardiometabolic disease risk. Methods: We compared metabolic parameters of individuals aged ≥10 years living in rural, high-helminth-transmission and urban, lower-helminth-transmission settings in Uganda. Cross-sectional surveys were conducted in rural Lake Victoria island fishing communities and in urban sub-wards in Entebbe municipality. Helminth infection and outcomes, including insulin resistance (computed using the homeostatic model assessment of insulin resistance [HOMA-IR]), fasting blood glucose, fasting blood lipids, blood pressure, body mass index (BMI), waist and hip circumference, were assessed. Results: We analysed 1,898 rural and 930 urban participants. Adjusting for BMI, exercise, smoking, alcohol intake, age and sex, urban residents had lower mean fasting glucose (adjusted mean difference [95%CI] 0.18 [-0.32, -0.05] p=0.01) and HOMA-IR (-0.26 [-0.40, -0.11] p=0.001) but higher blood pressure (systolic, 5.45 [3.75, 7.15] p<0.001; diastolic, 1.93 [0.57, 3.29] p=0.006). Current helminth infection did not explain the observed differences. Conclusions: In the Ugandan context, living in rural fishing communities may protect against hypertension but worsen glucose metabolism.

Effects of helminths and anthelmintic treatment on cardiometabolic diseases and risk factors: A systematic review

“…Fifteen different helminth species were represented, and these included Ancylostoma duodenale, Ascaris lumbricoides, Brugia malayi, Clonorchis sinensis, Fasciola hepatica, Necator americanus, Onchocerca volvulus, Opisthorchis viverinni, Schistosoma species (including S. haematobium, japonicum, and mansoni), Strongyloides stercoralifigs, Taenia solium, Trichuris trichiura, and Wuchereria bancrofti. Schistosoma species were most represented (S. mansoni (26), S. japonicum (8), unspecified Schistosoma species (7), and S. haematobium (2)) and studied in 43 studies, followed by mixed helminths (12), Strongyloides stercoralis (9), and others (20). The 34 records that did not meet Downs and Black criteria of "fair" or better quality are reported in S1 Supplemental Table . The associations of helminths with each of the 7 categories of cardiometabolic diseases and risk factors are discussed in the following sections.…”

“…Forty-three of these studies reported on total cholesterol [6][7][8][13][14][15][16][17]. Of these, 28 reported on participants infected with Schistosoma species or with mixed helminths that included Schistosoma species [6,7,13,15,[25][26][27][28]30,31,35,37,[39][40][41][42][43][44]46,[48][49][50][51][52][53][54][55].…”

“…Forty-three of these studies reported on total cholesterol [6][7][8][13][14][15][16][17]. Of these, 28 reported on participants infected with Schistosoma species or with mixed helminths that included Schistosoma species [6,7,13,15,[25][26][27][28]30,31,35,37,[39][40][41][42][43][44]46,[48][49][50][51][52][53][54][55]. These 28 studies mostly reported that infected individuals or those challenged with helminth products had lower total cholesterol than uninfected participants.…”

“…Previous systematic reviews have reported that helminth infections can be associated with favorable metabolic function and outcomes, but other cardiometabolic measures and the effects of anthelmintic treatment were not included [4,5]. Additionally, other studies have demonstrated inconsistency in the literature, with some showing that helminth infections worsened or had no effect on metabolic measures [6][7][8]. Against the backdrop of the World Health Organization's efforts to eliminate helminth infections by 2030 [9] and these previous data, we sought systematically to review data to investigate: (1) associations between helminth infections and cardiometabolic diseases and risk factors, and (2) whether helminth eradication could alter the prevalence and incidence of cardiometabolic diseases and risk factors.…”

Prevalence of Intestinal Helminth Coinfection in Drug-Resistant Tuberculosis in Uganda

“…Nonetheless, deworming was not associated with helminth coinfection in our study. Moreover, high rates of previous use of antihelminth medicine are reported in rural and urban Uganda, but this does not seem to affect the prevalence of helminth infection significantly [ 27 ]. There is also the possibility that community-wide de-worming campaigns and improvements in sanitation levels over the years have reduced the burden of intestinal parasites in Uganda [ 28 ].…”