During exercise, the sympathetic nervous system is activated, which causes vasoconstriction. The autonomic mechanisms responsible for this vasoconstriction vary based on the particular tissue being studied. Attempts to examine reflex control of the human renal circulation have been difficult because of technical limitations. In this report, the Doppler technique was used to examine renal flow velocity during four muscle contraction paradigms in conscious humans. Flow velocity was divided by mean arterial blood pressure to yield an index of renal vascular resistance (RVR). Fatiguing static handgrip (40% of maximal voluntary contraction) increased RVR by 76%. During posthandgrip circulatory arrest, RVR remained above baseline (2.1 +/- 0.2 vs. 2.8 +/- 0.2 arbitrary units; P < 0.017) but was only 40% of the end-grip RVR value. Voluntary biceps contraction increased RVR within 10 s of initiation of contraction. This effect was not associated with an increase in blood pressure. Finally, involuntary biceps contraction also raised RVR. We conclude that muscle contraction evokes renal vasoconstriction in conscious humans. The characteristic of this response is consistent with a primary role for mechanically sensitive afferents. This statement is based on the small posthandgrip circulatory arrest response and the vasoconstriction that was observed with involuntary biceps contraction.
Over 1.5 million women are victims of physical, sexual, and emotional abuse by former or present intimate partners. Intimate partner violence (IPV) around pregnancy can lead to devastating health consequences to mothers and infants. While some research suggests that IPV negatively affects the utilization of health services like prenatal care (PNC), inconsistencies in the assessment of PNC utilization, timing of partner violence, and definitions of IPV yield conflicting results. The objective for the present study is to evaluate whether preconception IPV, prenatal IPV, or IPV in the preconception and/or prenatal period affects PNC utilization. This study analyzed the 2004-2008 national Pregnancy Risk Assessment Monitoring System (PRAMS), which included 202,367 women who delivered a live birth in the United States. IPV victimization was measured using four items that addressed physical abuse by a current or former husband/partner in the 12 months before (preconception) and during (prenatal) pregnancy. Responses were categorized as preconception, prenatal, and preconception and/or prenatal IPV. The outcome was PNC adequacy categorized as inadequate, intermediate, adequate, and adequate plus based on the Adequacy of Prenatal Care Utilization index. Separate logistic regression models provided crude and adjusted odds ratios and 95% confidence intervals (CI). Over 6% of women reported preconception and/or prenatal IPV and 26% had less than adequate PNC. Women who reported abuse before and/or during pregnancy were more likely to have inadequate PNC (odds ratio [OR] = 1.4, 95% CI = [1.3, 1.6]). Similarly, women who experienced preconception or prenatal IPV were 30% more likely to have inadequate PNC (OR = 1.3, 95% CI = [1.2, 1.5]; OR = 1.3, 95% CI = [1.1, 1.7], respectively). Adequate PNC is essential in improving pregnancy outcomes; however, women in abusive relationships may face ongoing challenges and difficulties with obtaining appropriate care. Findings underscore a critical problem and health providers are urged to screen and educate women about IPV during all preconception and prenatal visits.
Prepregnancy BMI is a significant predictor for breastfeeding noninitiation for non-Hispanic white and non-Hispanic black women. Further exploration of the differences underlying the association between prepregnancy BMI and breastfeeding behaviors among racial subpopulations of women in the United States is warranted.
Our results highlight factors associated with attendance of PPCVs in low income populations. The continued disparity in postpartum care utilization compels additional efforts to improve access to health services across socioeconomic and demographic boundaries.
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