Aims: 

Gestational diabetes mellitus (GDM) is thought to be an early manifestation of metabolic syndrome, as it is characterized by significant insulin resistance. Postocclusive reactive hyperemia (PORH) is a complex microvascular reaction that is a marker of endothelial function. Our aim was to investigate early microcirculatory changes and endothelial dysfunction in women with a history of GDM.

Methods: 

In this case-control study we investigated correlates of the PORH-index (PORHi) among 40 women with a history of gestational diabetes (GDM) and 28 controls (age (mean±SD): 36.9±4.0 vs. 34.8±2.9 yrs, P=0.013, BMI: 27.2±6.5 vs. 24.7±5.0 kg/m², PNS) 3.3±0.5 years after delivery. Endothelium-dependent vasodilatation was measured using laser-Doppler flowmetry (Perimed, Sweden). The main outcome was the PORHi (the percentage increase in cutaneous blood flow from resting conditions to peak dilation following a 2 min upper arm occlusion).

Results: 

The PORHi was lower in prior GDM cases than in controls (3.23±0.97 vs. 3.80±1.18; P=0.032). The prior GDM group had a higher waist to hip ratio (0.82±0.07 vs. 0.78±0.06), blood pressure (125±17/79±11 vs. 116±14/72±12 mmHg), HbA1c (5.6±0.3 vs. 5.4±0.3%), fasting (5.7±0.9 vs.5.2±0.5 mmol/l) and 2-hour glucose (7.2±2.4 vs. 5.6±1.2 mmol/l), and 2-hour insulin (82±62 vs.43±28 mIU/ml, all P<0.05). Negative correlation (all P<0.05) was found between the PORHi and priorGDM status (r=-0.253), white blood cell count (WBC, r=-0.278), lipoprotein(a) (lp(a), r=-0.248), insulin (r=-0.252), and diastolic blood pressure (r=-0.259); while the PORHi was positively related to serum total cholesterol (r=0.278; P=0.022). According to a multiple linear regression model the PORHi was independently related to prior GDM status, WBC, lp(a), and serum cholesterol.

Conclusion: 

We found that prior GDM women had impaired endothelial function. Furthermore lower PORH-index was related to higher white blood cell count and lipoprotein(a) suggesting that subclinical inflammation and the coagulation system are both involved in the development of endothelial dysfunction.