Table 2.
Clinical and metabolic variables in different quartiles of prolactin levels
| Clinical and metabolic variables | Quartile 1 ≤34.85 (n = 50) |
Quartile 2 >34.85-60.88(n = 50) |
Quartile 3 >60.88-126.24(n = 50) |
Quartile 4 >126.24 (n = 50) |
P value |
|---|---|---|---|---|---|
| Age, mean (SD) | 33.3 (5.5) | 33.5 (4.9) | 34.1 (4.8) | 34.2 (5.5) | 0.800 |
| Pre-pregnancy BMI, kg/m2, mean (SD) | 35.1 (9.5) | 33.3 (7.8) | 33.3 (7.2) | 30.2 (7.1) | 0.024 |
| Race,n (%) | 0.398 | ||||
| Non-Hispanic White | 10 (20%) | 8 (16%) | 9 (18%) | 5 (10%) | |
| Asian | 15 (30%) | 19 (38%) | 19 (38%) | 19 (38%) | |
| Non-Hispanic Black | 9 (18%) | 6 (12%) | 2 (4%) | 3 (6%) | |
| Hispanic | 16 (32%) | 14 (28%) | 20 (40%) | 22 (44%) | |
| Other | 0 (0%) | 3 (6%) | 0 (0%) | 1 (2%) | |
| Prenatal 3-hour 100-g OGTT z-score sum, mean (SD) | 0.17 (2.34) | 0.71 (3.12) | 0.98 (2.64) | 0.28 (2.89) | 0.417 |
| GDM treatment, n (%) | 0.046 | ||||
| Insulin or oral medicine | 27 (54%) | 14 (28%) | 23 (46%) | 18 (36%) | |
| Diet | 23 (46%) | 36 (72%) | 27 (54%) | 32 (64%) | |
| Gestational weight gain, kg, mean (SD) | 8.8 (7.0) | 9.2 (8.9) | 7.7 (6.3) | 10.1 (6.1) | 0.394 |
| Baseline variables (6-9 weeks post-delivery) | |||||
| BMI, kg/m2, mean (SD) | 35.2 (8.6) | 33.5 (7.0) | 32.5 (6.7) | 30.7 (6.4) | 0.019 |
| LIR 2-month intensity score, median(IQR) | 0.71 (0.30-1.70) | 1.73 (0.90-2.00) | 1.96 (1.60-2.00) | 1.92 (1.68-2.00) | <0.001 |
| Total lactation duration, months, median (IQR) | 1.4 (0.7-3.8) | 5.0 (2.3-11.5) | 8.7 (4.3-13.1) | 11.4 (6.2-12.9) | <0.001 |
| FPG, mg/dL, mean (SD) | 100.8 (10.2) | 97.1 (10.9) | 98.7 (10.2) | 94.5 (8.3) | 0.015 |
| 2h-PG, mg/dL, mean (SD) | 117.5 (28.4) | 117.6 (26.8) | 127.3 (36.0) | 115.3 (31.3) | 0.214 |
| Fasting insulin, mU/mL, mean (SD) | 31.8 (17.4) | 29.9 (19.0) | 24.6 (12.2) | 23.6 (12.5) | 0.023 |
| HOMA-IR, median (IQR) | 7.7 (4.5-10.4) | 5.9 (3.9-9.1) | 5.4 (3.7-7.8) | 4.5 (3.5-7.4) | 0.026 |
| Fasting TAG, mg/dL, median (IQR) | 115.5 (72.8-179.0) | 107 (75.8-168.3) | 105.5 (69.0-163.8) | 93.5 (72.5-130.0) | 0.556 |
| Fasting HDL-C, mg/dL, mean (SD) | 47.9 (12.4) | 50.0 (13.7) | 48.8 (11.7) | 56.1 (14.0) | 0.008 |
| Leptin, mean (SD) | 37.0 (16.1) | 35.6 (16.8) | 29.6 (15.9) | 28.5 (14.9) | 0.014 |
| Adiponectin, median (IQR) | 6.4 (5.8-8.2) | 6.5 (4.9-8.8) | 7.1 (5.2-8.4) | 7.3 (5.1-8.6) | 0.929 |
Normal distribution was checked through histogram and Q-Q plot. Data are presented as mean (SD) for continuous variables that are approximately normally distributed. Data are presented as median (IQR) for continuous variables with asymmetrical distributions. Chi-square test was used for categorical variables (n, %), 1-way ANOVA was used for continuous variables (mean, SD), and Kruskal-Wallis test was used for continuous variables (median, IQR). A Tukey post hoc test was performed for relationships that were found to be statistically significant.
Abbreviations: 2h-PG, 2-hour post-load plasma glucose; BMI, body mass index; FPG, fasting plasma glucose; HDL-C, high-density lipoprotein cholesterol; HOMA-IR, homeostatic model assessment for insulin resistance; LIR, lactation intensity/duration ratio; TAG, triglyceride.