Analysis of correlations between <i>Loa loa</i> microfilarial status and densities, lipid profile and glycated hemoglobin.

1 Fisher’s exact test. 2 Cramér’s V. 3 Cuzick’s test. * For lipid panel, an individual is considered out of range if at least one of the lipids is out of range (see S2 and S3 Tables). (DOCX)</p

Flowchart of the study.

BackgroundLoa loa filariasis (loiasis) is still considered a relatively benign disease. However, recent epidemiologic data suggest increased mortality and morbidity in L. loa infected individuals. We aimed to examine whether the density of L. loa microfilariae (mfs) in the blood is associated with cardiovascular disease.MethodologyUsing a point-of-care device (pOpmètre), we conducted a cross-sectional study to assess arterial stiffness and peripheral arterial disease (PAD) in 991 individuals living in a loiasis-endemic rural area in the Republic of the Congo. Microfilaremic individuals were matched for age, sex and village of residence with 2 amicrofilaremic subjects.We analyzed markers of arterial stiffness (Pulse-Wave Velocity, PWV), PAD (Ankle-Brachial Index, ABI) and cardiovascular health (Pulse Pressure, PP). The analysis considered parasitological results (L. loa microfilarial density [MFD], soil-transmitted helminths infection, asymptomatic malaria and onchocerciasis), sociodemographic characteristics and known cardiovascular risk factors (body mass index, smoking status, creatininemia, blood pressure).Principal findingsAmong the individuals included in the analysis, 192/982 (19.5%) and 137/976 (14.0%) had a PWV or an ABI considered out of range, respectively. Out of range PWV was associated with younger age, high mean arterial pressure and high L. loa MFD. Compared to amicrofilaremic subjects, those with more than 10,000 mfs/mL were 2.17 times more likely to have an out of range PWV (p = 0.00). Factors significantly associated with PAD were older age, low pulse rate, low body mass index, smoking, and L. loa microfilaremia. Factors significantly associated with an elevation of PP were older age, female sex, high average blood pressure, low pulse rate and L. loa microfilaremia.ConclusionA potential link between high L. loa microfilaremia and cardiovascular health deterioration is suggested. Further studies are required to confirm and explore this association.</div

Results from logistic regression model explaining Pulse Wave Velocity status.

Results from logistic regression model explaining Pulse Wave Velocity status.</p

Results from logistic regression model explaining the presence of Peripheral Arterial Disease.

Results from logistic regression model explaining the presence of Peripheral Arterial Disease.</p

Distribution of the main characteristics according to Pulse Wave Velocity status (using References values #2).

Abbreviations: PWV, pulse wave velocity; N, number; SD, Standard deviation; MFD, microfilarial density; IQR, interquartile range; N/A, not applicable. * Chi-2 for categorical variable and Kruskal-Wallis rank test for continuous variables. ** An individual is defined as out of range if his/her PWV is higher than the 90th percentile of the population considered healthy in the same age category (see S1 Table 1 –References values #2). (DOCX)</p

Distribution of the main characteristics according to Pulse Wave Velocity status.

Distribution of the main characteristics according to Pulse Wave Velocity status.</p

Pulse Wave Velocity measurements.

Abbreviations: N, number of subjects in the category; MFD, microfilarial density. * Values calculated from individuals with no hypertension (defined as SBP L. loa microfilaremia. ** Values calculated from individuals with no hypertension (defined as DPB L. loa microfilaremia. (DOCX)</p

Lipid profile and glycated hemoglobin according to the PWV status.

Abbreviations: PWV, pulse wave velocity; N., number; Hb1AC, glycated hemoglobin; SD, standard deviation; IQR, interquartile range; HDL, high density lipoprotein; LDL, low density lipoprotein; NA, not applicable. * An individual is defined as out of range if its PWV is higher than the 90th percentile of the population considered healthy in the same age category (see S1 Table–References values #1). ** Threshold at which the measurement is considered out of range: Hb1Ac >7%; Total cholesterol >5 mmol/L; Triglycerides >1.7 mmol/L; HDL 3.5 mmol/L; for lipid panel, measurement is considered out of range if one of the lipids is out of range. *** Chi-2 test for categorical variables with all effectives > 5 or fisher’s exact test. (DOCX)</p

Results from logistic regression model explaining Pulse Wave Velocity status (using References values #2).

Abbreviations: PWV, pulse wave velocity; bpm, beats per minute; aOR, adjusted odds-ratio; CI, confidence intervals. * An individual is defined as out of range if his/her PWV is higher than the 90th percentile of the population considered healthy in the same age category (see S1 Table–References values #2). (DOCX)</p

Lipid profile and glycated hemoglobin according to the PAD.

Abbreviations: PAD, peripherical arterial disease; N., number; Hb1AC, glycated hemoglobin; SD, standard deviation; IQR, interquartile range; HDL, high density lipoprotein; LDL, low density lipoprotein; NA: not applicable. * Threshold at which the measurement is considered out of range: Hb1Ac >7%; Total cholesterol >5 mmol/L; Triglycerides >1.7 mmol/L; HDL 3.5 mmol/L; for lipid panel, measurement is considered out of range if one of the lipids is out of range. ** Chi-2 test for categorical variables with all effectives > 5 or fisher’s exact test. (DOCX)</p