Table 2.
Adjusted odds ratios and 95% CIs for asthenozoospermia by tertile of dietary fat and fatty acid intake.
| Variables | Cases (N = 549) | Controls (N = 581) | Multivariable-adjusted models |
||
|---|---|---|---|---|---|
| Model 1 | Model 2 | Model 3 | |||
| Total fat (g/day) † | |||||
| T1 (<46.60) | 185 | 193 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| T2 (46.60 to <53.56) | 178 | 193 | 1.02 (0.76–1.36) | 1.08 (0.80–1.45) | 0.97 (0.70–1.33) |
| T3 (≥53.56) | 186 | 195 | 1.01 (0.76–1.35) | 1.08 (0.80–1.45) | 0.84 (0.56–1.27) |
| Continuous (per SD increment) | 1.00 (0.89–1.13) | 1.03 (0.91–1.16) | 0.89 (0.73–1.08) | ||
| P for trend* | 0.95 | 0.62 | 0.40 | ||
| Animal-based fat (g/day) † | |||||
| T1 (<24.23) | 203 | 193 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| T2 (24.23 to <30.15) | 177 | 193 | 1.12 (0.84–1.50) | 1.10 (0.82–1.47) | 1.07 (0.78–1.45) |
| T3 (≥30.15) | 169 | 195 | 1.25 (0.94–1.67) | 1.27 (0.95–1.71) | 1.19 (0.82–1.73) |
| Continuous (per SD increment) | 1.13 (1.00–1.27) | 1.14 (1.01–1.28) | 1.14 (0.96–1.36) | ||
| P for trend* | 0.13 | 0.10 | 0.37 | ||
| Plant-based fat (g/day) † | |||||
| T1 (<20.12) | 156 | 193 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| T2 (20.12 to <24.85) | 169 | 193 | 0.83 (0.52–1.32) | 0.91 (0.67–1.24) | 0.90 (0.66–1.23) |
| T3 (≥24.85) | 224 | 195 | 0.67 (0.50–0.90) | 0.72 (0.53–0.97) | 0.68 (0.50–0.92) |
| Continuous (per SD increment) | 0.85 (0.76–0.96) | 0.87 (0.77–0.99) | 0.85 (0.75–0.97) | ||
| P for trend* | <0.05 | <0.05 | <0.05 | ||
| Total FA (g/day) † | |||||
| T1 (<35.15) | 196 | 193 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| T2 (35.15 to <41.49) | 170 | 193 | 1.12 (0.83–1.49) | 1.13 (0.84–1.51) | 1.05 (0.77–1.43) |
| T3 (≥41.49) | 183 | 195 | 1.08 (0.81–1.44) | 1.13 (0.84–1.51) | 0.96 (0.66–1.39) |
| Continuous (per SD increment) | 1.07 (0.95–1.21) | 1.10 (0.97–1.24) | 1.05 (0.89–1.24) | ||
| P for trend* | 0.61 | 0.42 | 0.83 | ||
| Total SFA (g/day) † | |||||
| T1 (<13.87) | 211 | 193 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| T2 (13.87 to <16.60) | 172 | 193 | 1.17 (0.87–1.56) | 1.20 (0.90–1.61) | 1.16 (0.85–1.57) |
| T3 (≥16.60) | 166 | 195 | 1.25 (0.94–1.66) | 1.33 (0.99–1.78) | 1.24 (0.89–1.73) |
| Continuous (per SD increment) | 1.10 (0.98–1.24) | 1.13 (1.00–1.28) | 1.10 (0.96–1.27) | ||
| P for trend* | 0.13 | 0.06 | 0.21 | ||
| Short-to-medium-chain SFA a (g/day)† | |||||
| T1 (<0.56) | 172 | 193 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| T2 (0.56 to <0.84) | 173 | 193 | 0.92 (0.68–1.24) | 0.97 (0.72–1.32) | 0.97 (0.72–1.32) |
| T3 (≥0.84) | 204 | 195 | 0.78 (0.58–1.04) | 0.84 (0.62–1.13) | 0.83 (0.61–1.11) |
| Continuous (per SD increment) | 0.93 (0.83–1.05) | 0.96 (0.85–1.09) | 0.95 (0.84–1.08) | ||
| P for trend* | 0.09 | 0.23 | 0.18 | ||
| Long-chain SFA b (g/day)† | |||||
| T1 (<13.80) | 217 | 193 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| T2 (13.80 to <16.38) | 167 | 193 | 1.23 (0.92–1.65) | 1.25 (0.94–1.68) | 1.22 (0.90–1.66) |
| T3 (≥16.38) | 165 | 195 | 1.32 (0.99–1.76) | 1.38 (1.03–1.85) | 1.31 (0.93–1.85) |
| Continuous (per SD increment) | 1.13 (1.00–1.27) | 1.16 (1.02–1.31) | 1.14 (0.98–1.32) | ||
| P for trend* | 0.06 | <0.05 | 0.12 | ||
| Total MUFA (g/day) † | |||||
| T1 (<14.26) | 211 | 193 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| T2 (14.26 to <16.96) | 170 | 193 | 1.22 (0.91–1.62) | 1.24 (0.93–1.66) | 1.20 (0.88–1.63) |
| T3 (≥16.96) | 168 | 195 | 1.28 (0.96–1.71) | 1.31 (0.98–1.75) | 1.21 (0.85–1.73) |
| Continuous (per SD increment) | 1.09 (0.97–1.23) | 1.11 (0.98–1.25) | 1.07 (0.91–1.25) | ||
| P for trend* | 0.09 | 0.07 | 0.28 | ||
| Animal-based MUFA (g/day) † | |||||
| T1 (<8.12) | 215 | 193 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| T2 (8.12 to <10.68) | 187 | 193 | 1.11 (0.84–1.47) | 1.09 (0.82–1.46) | 1.09 (0.81–1.47) |
| T3 (≥10.68) | 147 | 195 | 1.50 (1.12–2.01) | 1.49 (1.11–2.00) | 1.49 (1.04–2.14) |
| Continuous (per SD increment) | 1.21 (1.07–1.36) | 1.20 (1.06–1.36) | 1.24 (1.05–1.45) | ||
| P for trend* | <0.05 | <0.05 | <0.05 | ||
| Plant-based MUFA (g/day) † | |||||
| T1 (<5.15) | 165 | 193 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| T2 (5.15 to <6.70) | 179 | 193 | 0.87 (0.64–1.17) | 0.91 (0.67–1.24) | 0.91 (0.66–1.23) |
| T3 (≥6.70) | 205 | 195 | 0.79 (0.59–1.06) | 0.84 (0.63–1.13) | 0.81 (0.60–1.10) |
| Continuous (per SD increment) | 0.89 (0.79–1.00) | 0.91 (0.80–1.02) | 0.89 (0.79–1.01) | ||
| P for trend* | 0.12 | 0.26 | 0.17 | ||
| Total PUFA (g/day) † | |||||
| T1 (<6.16) | 193 | 193 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| T2 (6.16 to <7.62) | 152 | 193 | 1.24 (0.92–1.68) | 1.28 (0.94–1.74) | 1.21 (0.88–1.65) |
| T3 (≥7.62) | 204 | 195 | 0.98 (0.74–1.30) | 1.02 (0.76–1.36) | 0.87 (0.62–1.23) |
| Continuous (per SD increment) | 0.95 (0.84–1.07) | 0.96 (0.85–1.09) | 0.86 (0.73–1.01) | ||
| P for trend* | 0.78 | 0.96 | 0.37 | ||
| Total omega-3 PUFA c (g/day)† | |||||
| T1 (<0.72) | 194 | 193 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| T2 (0.72 to <0.90) | 151 | 193 | 1.27 (0.94–1.71) | 1.26 (0.93–1.71) | 1.17 (0.85–1.62) |
| T3 (≥0.90) | 204 | 195 | 1.00 (0.75–1.32) | 1.03 (0.77–1.37) | 0.87 (0.61–1.25) |
| Continuous (per SD increment) | 1.02 (0.90–1.14) | 1.02 (0.91–1.15) | 0.94 (0.78–1.12) | ||
| P for trend* | 0.86 | 0.97 | 0.38 | ||
| Total omega-6 PUFA d (g/day)† | |||||
| T1 (<5.44) | 190 | 193 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| T2 (5.44 to <6.71) | 146 | 193 | 1.26 (0.93–1.71) | 1.33 (0.97–1.82) | 1.25 (0.91–1.73) |
| T3 (≥6.71) | 213 | 195 | 0.92 (0.69–1.22) | 0.96 (0.72–1.28) | 0.81 (0.58–1.13) |
| Continuous (per SD increment) | 0.94 (0.83–1.06) | 0.95 (0.84–1.07) | 0.86 (0.74–0.99) | ||
| P for trend* | 0.42 | 0.57 | 0.15 | ||
| Marine omega-3 PUFA e (g/day)† | |||||
| T1 (<0.04) | 195 | 193 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| T2 (0.04 to <0.09) | 176 | 193 | 1.11 (0.83–1.49) | 1.08 (0.81–1.44) | 1.05 (0.78–1.41) |
| T3 (≥0.09) | 178 | 195 | 1.17 (0.88–1.57) | 1.13 (0.84–1.51) | 1.08 (0.80–1.47) |
| Continuous (per SD increment) | 1.09 (0.97–1.23) | 1.08 (0.96–1.22) | 1.06 (0.93–1.21) | ||
| P for trend* | 0.30 | 0.43 | 0.62 | ||
| Omega-6/omega-3 ratio † | |||||
| T1 (<6.91) | 173 | 193 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| T2 (6.91 to <7.92) | 158 | 193 | 1.08 (0.80–1.45) | 1.09 (0.81–1.48) | 1.10 (0.81–1.49) |
| T3 (≥7.92) | 218 | 195 | 0.77 (0.58–1.02) | 0.78 (0.59–1.04) | 0.79 (0.59–1.08) |
| Continuous (per SD increment) | 0.92 (0.82–1.04) | 0.93 (0.82–1.05) | 0.94 (0.83–1.07) | ||
| P for trend* | <0.05 | 0.06 | 0.09 | ||
FA, fatty acid; MUFA, monounsaturated fatty acid; PUFA, polyunsaturated fatty acid; Ref, reference; SFA, saturated fatty acid; T, tertile.
The SD for the listed fat and FAs are 8.75, 8.12, 6.83, 8.17, 3.66, 0.40, 3.59, 3.62, 3.31, 2.48, 2.22, 0.29, 1.99, 0.07, and 1.69 g/day, respectively.
Model 1: adjusted for age (continuous, years) and total energy intake (continuous, kcal/day).
Model 2: same as Model 1 and further adjusted for BMI (continuous, kg/m2), alcohol drinking (yes or no), cigarette smoking (yes or no), dietary change (yes or no), household income (<50, 50 to <100, or ≥100, thousand yuan), education (junior secondary or below, senior high school/technical secondary school, and junior college/university or above), physical activity (continuous, metabolic equivalent/hours/week), and abstinence time (continuous, days).
Model 3: same as Model 2 and further adjusted for total protein (continuous, g/day) and total carbohydrate (continuous, g/day) intake.
Adjusted for energy by the residual method.
P value for linear trend calculated from category median values.
Short-to-medium-chain SFA included saturated butyric (C4), caproic (C6), caprylic (C8), capric (C10), undecanoic (C11), lauric (C12), and tridecanoic (C13) acids.
Long-chain SFA included saturated myristic (C14), pentadecanoic (C15), palmitic (C16), heptadecanoic (C17), stearic (C18), nonadecanoic (C19), arachidic (C20), behenic (C22), and lignoceric (C24) acids.
Total omega-3 PUFA included alpha-linolenic acid, parinaric acid, docosatrienoic acid, eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA).
Total omega-6 PUFA included linoleic acid, eicosadienoic acid, arachidonic acid, and docosatetraenoic acid.
Marine omega-3 PUFA included eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA).