Table 3

Association of risk factors with acute kidney injury† based on logistic regression (n=283)

Age-adjusted and sex-adjusted modelModel adding physiological factorsModel adding occupational factors
AOR95% CIp ValueAOR95% CIp ValueAOR95% CIp Value
Per cent body mass lost‡0.660.42 to to to 1.170.18
Heat strain§1.291.03 to 1.610.03*1.341.03 to 1.650.03*1.341.04 to 1.740.02*
Age in years0.990.97 to 1.020.650.990.95 to 1.020.420.980.94 to 1.020.34
 Male (reference)
 Female1.460.65 to 3.260.361.440.60 to 3.440.412.120.80 to 5.630.13
 Normal weight (<25) (reference)
 Overweight (25–30)0.390.15 to to 1.090.07*
 Obese (>30)0.290.10 to 0.820.02*0.320.11 to 0.960.04*
 HbA1c<5.7% (reference)
 HbA1c≥5.7%2.450.93 to 6.460.072.630.93 to 7.410.07
Blood pressure††
 Normal blood pressure (<120/80) (reference)
 Prehypertensive (120–139/80–89)0.640.24 to 1.700.370.730.26 to 2.060.56
 Hypertension (≤140/90)0.740.24 to 2.230.590.940.29 to 2.990.91
History of kidney disease
 None (reference)
 Personal or family history1.350.58 to 3.130.491.640.680 to 3.980.27
Years in agricultural work1.030.98 to 1.080.21
Payment method
 Hourly/salary (reference)
 Piece rate4.241.56 to 11.520.01*
Farm task
 Picking1.10.41 to 2.920.86
 Other (reference)‡‡
Model fit statistics
  • *Significant at α<0.05.

  • †Acute kidney injury based on KDIGO classification of elevations in serum creatinine.

  • ‡Per cent body mass lost based on comparing preshift weight in kilograms and postshift weight in kilograms.

  • §Heat strain estimated by PSI with PSI≥7.5 signifying heat strain; Centered at PSI-4.

  • ¶BMI (kg/m2) categorized based on WHO recommendations.

  • **HgbA1c from capillary blood sample.

  • ††Blood pressure based on JNC7 categories.

  • ‡‡Other includes all other farm tasks except picking.

  • AOR, adjusted OR;

  • BMI, body mass index; HbA1c, glycated haemoglobin; KDIGO, Kidney Disease: Improving Global Outcomes; PSI, physiological strain index.