Introduction
Methods
Patient selection
Data collection
Statistical analysis
Results
Summer (SD) | Autumn (SD) | Winter (SD) | Spring (SD) | p value | |
---|---|---|---|---|---|
Mean age (years) | 29.6 (5.3) | 29.4 (5.3) | 29.4 (5.5) | 29.5 (5.4) | = 0.953 |
Anglo-Saxon descent | 90.8% | 92.1% | 91.2% | 91.6% | = 0.895 |
Mean BMI (kg/m2) | 29.1 (6.0) | 29.1 (5.7) | 29.4 (5.8) | 29.1 (5.8) | = 0.741 |
Mean gestational age (weeks) | 28.2 (1.5) | 28.1 (1.4) | 28.2 (1.2)) | 28.1 (1.3) | = 0.8316 |
Summer (SD) mmol/L n = 476 | Autumn (SD) mmol/L n = 530 | Winter (SD) mmol/L n = 558 | Spring (SD) mmol/L n = 558 | p value | |
---|---|---|---|---|---|
Fasting plasma glucose | 4.4 (0.4) | 4.5 (0.4) | 4.5 (0.4) | 4.5 (0.4) | < 0.001 |
1-h plasma glucose | 7.6 (1.7) | 7.4 (1.5) | 7.4 (1.5) | 7.4 (1.6) | = 0.002 |
2-h plasma glucose | 6.4 (1.3) | 6.3 (1.3) | 6.1 (1.2) | 6.3 (1.4) | < 0.001 |
HbA1c | 4.7 (0.3) | 4.8 (0.4) | 4.8 (0.4) | 4.7 (0.4) | < 0.001 |
HOMA-IR | 7.5 (4.0) | 8.1 (4.4) | 8.4 (4.5) | 8.1 (4.6) | = 0.014 |
1-h plasma glucose | Autumn | Spring | = 1 |
Summer | = 0.376 | ||
Winter | = 0.308 | ||
Spring | Autumn | = 1 | |
Summer | = 0.504 | ||
Winter | = 0.196 | ||
Summer | Autumn | = 0.376 | |
Spring | = 0.504 | ||
Winter | = 0.001 | ||
Winter | Autumn | = 0.308 | |
Spring | = 0.196 | ||
Summer | = 0.001 | ||
2-h plasma glucose | Autumn | Spring | = 1 |
Summer | = 0.491 | ||
Winter | = 0.110 | ||
Spring | Autumn | = 1 | |
Summer | = 1 | ||
Winter | = 0.012 | ||
Summer | Autumn | = 0.491 | |
Spring | = 1 | ||
Winter | < 0.0001 | ||
Winter | Autumn | = 0.110 | |
Spring | = 0.012 | ||
Summer | < 0.0001 |
Summer (%) n = 476 | Autumn (%) n = 530 | Winter (%) n = 558 | Spring (%) n = 558 | p value | |
---|---|---|---|---|---|
GDM prevalence by fasting plasma glucose ≥5.1 mmol/L n = 79 | 5.5% | 6.4% | 9.5% | 8.4% | = 0.055 |
GDM prevalence by 1-h post-load glucose ≥10.0 mmol/L n = 31 | 6.5% | 3.6% | 2.5% | 3.2% | = 0.009 |
GDM prevalence by 2-h post-load glucose ≥8.5 mmol/L n = 12 | 4.2% | 3.2% | 1.6% | 4.7% | = 0.033 |
Overall GDM prevalence by WHO criteria n = 122 | 13.9% | 12.1% | 12.9% | 15.1% | = 0.510 |
Correlation with average monthly temperature | Pearson’s r | p value |
---|---|---|
Fasting plasma glucose | - 0.145 (−0.187, − 0.103) | < 0.001 |
1-h plasma glucose | + 0.079 (+ 0.036, + 0.120) | < 0.001 |
2-h plasma glucose | + 0.093 (+ 0.051, + 0.135) | < 0.001 |
HbA1c | - 0.069 (−0.113, − 0.025) | = 0.002 |
Summer (SD) mmol/L n = 476 | Autumn (SD) mmol/L n = 530 | Winter (SD) mmol/L n = 558 | Spring (SD) mmol/L n = 558 | p value | |
---|---|---|---|---|---|
Umbilical cord C-peptide | 0.993 (0.557) | 1.062 (0.661) | 1.076 (0.646) | 0.996 (0.538) | = 0.087 |
Umbilical cord glucose | 4.658 (1.180) | 4.754 (1.187) | 4.758 (1.219) | 4.578 (1.096) | = 0.066 |
Correlation with average monthly temperature | Pearson’s r | p value |
---|---|---|
Umbilical cord C-peptide (n = 1721) | - 0.153 (−0.199, −0.107) | < 0.001 |
Umbilical cord glucose (n = 1694) | - 0.126 (−0.172, − 0.079) | < 0.001 |