Exploring the Potential Role of Family History of Hypertension on Racial Differences in Sympathetic Vascular Transduction

The prevalence of hypertension in Non-Hispanic Black (BL) men surpasses all other racial groups. Our laboratory has previously demonstrated exaggerated vasoconstrictor and blood pressure (BP) responses to spontaneous bursts of muscle sympathetic nerve activity (MSNA; sympathetic vascular transduction) in young, healthy BL men compared to their Non-Hispanic White (WH) counterparts. Because a family history of hypertension (FHH) further compounds cardiovascular risk, we wanted to begin to explore the potential impact of a positive (+) FHH on sympathetic vascular transduction. Whether a +FHH influences sympathetic vascular transduction in WH and/or BL men remains unknown. PURPOSE: To begin to explore if +FHH influences sympathetic vascular transduction within and between racial groups. METHODS: 22 men, nine with a +FHH (4 BL men) and 13 without a FHH (-FHH; 6 BL men) were recruited. Beat-to-beat BP (Finometer), femoral artery blood flow (Doppler ultrasound), and MSNA were measured during a 20-minute quiet rest. The mean BP and leg vascular conductance (LVC; blood flow/mean BP) responses to spontaneous bursts of MSNA were quantified via a signal averaging technique. RESULTS: Resting heart rate, BP, and MSNA were not significantly different between groups (all p\u3e0.05). As previously demonstrated by our laboratory, the BL men exhibited an augmented sympathetic vascular transduction compared to the WH men (e.g., peak BP response, WH men: Δ4.1±0.3, BL men: Δ5.6±0.7 mmHg, p=0.04). When accounting for FHH within the groups, the peak BP (WH +FHH: Δ4.4±0.6 vs. WH -FHH: Δ3.8±0.4 mmHg, p=0.4) and nadir LVC responses (WH +FHH: Δ-0.5±0.07 vs. WH -FHH: Δ-0.5±0.09 ml·min-¹·mmHg-¹, p=0.7) were not significantly different between WH men +FHH and WH men –FHH. Likewise, the BL men +FHH exhibited similar peak BP (BL +FHH: Δ6.2±0.7 vs. BL -FHH: Δ5.3±1.1 mmHg, p=0.5) and nadir LVC (BL +FHH: Δ-1.1±0.44 vs. BL -FHH: Δ-0.6±0.10 ml·min-¹·mmHg-¹, p=0.2) responses to bursts of MSNA compared to the BL men –FHH. CONCLUSION: These preliminary findings do not support a role for +FHH in augmented sympathetic vascular transduction, therefore suggesting that racial differences in sympathetic vascular transduction are independent of FHH

One size fits all? Female Headed Households, Income Risk, and Access to Resources

Studies dealing with productivity in female (FHH) and male headed households (MHH) find that FHH appear to be either less, equally, or more productive compared to MHH. Lower productivity of FHH is often explained by insecure access to land, while the findings of higher productivity largely remain unexplained. This paper is an attempt to reconcile these contrasting findings by constructing a model that accounts for productivity effects arising from secure land rights and the risk of falling short of income. Both affect productivity, but they do so in opposite directions. While tenure insecurity tends to decrease labor effort, income risks increase it as subsistence farmers want to avoid falling (deeper) into poverty. Depending on which of these risks prevails in the perception of farmers, they become either more or less productive than a benchmark farmer who faces none of these constraints. The model is tested using data from Kenya where FHH are categorized by different land tenure security schemes. The results from a stochastic cost frontier model establish that FHH facing tenure insecurity are less productive compared to MHH. However, this result only obtains in case households do not face income risks.Female headed households, tenure insecurity, income risk, Consumer/Household Economics,

Exercise Pressor Response in Hispanic Adults with Family History of Hypertension

Family history of hypertension (FHH), being an unmodifiable risk factor, increases probability of developing hypertension and other cardiovascular diseases. The prevalence of hypertension in Hispanic/Latino (H/La) males is 50.3%, while it is 48.9% in non-Hispanic white (NHW) males and 57.5% in non-Hispanic black (NHB) males. Among adolescents aged 8 to 17, H/La youth has the highest incidence of hypertension as compared to all other races. It is evident that young normotensive adults with positive family history of hypertension (+FHH) exhibit exaggerated exercise pressor response. Additionally, a higher sympathetic activity to cold pressor test (CPT) was found in normotensive NHB adults with +FHH. However, the potential effect of +FHH in H/La population remains unexplored. PURPOSE: In this study we investigated the effect of +FHH on the pressor response during exercise and CPT in H/La adults with +FHH and without family history of hypertension (-FHH). METHODS: In 5 H/La adults with +FHH (age = 24 ± 4 mmHg; BMI = 24 ± 3 kg/m2; MVC = 76 ± 9 kg) and 6 H/La adults with -FHH (age = 21 ± 0.4 years; BMI = 24 ± 1 kg/m2; MVC = 82 ± 10 kg), beat-to-beat blood pressure (finger plethysmography) and heart rate (ECG) were measured at rest and during 2 minutes of static handgrip exercise performed at 30% and 40% of their maximum voluntary contraction (MVC). Muscle metaboreflex was isolated by post exercise ischemia (PEI; supra-systolic cuff (220 mmHg) inflation on the exercising arm) for 2 minutes and 15 seconds. We further investigated the pressor response to CPT, a generalized sympatho-excitatory stimulus, by putting the hand in ice water for 2 minutes. RESULTS: Resting mean arterial pressure (MAP) was not different between groups (+FHH = 78 ± 6 mmHg; -FHH = 79 ± 8 mmHg; p= 0.9). The exercise pressor response at 30% MVC (+FHH = 26 ± 7mmHg; -FHH = 27 ± 8 mmHg; p = 0.9) and 40% (+FHH = 46 ± 8 mmHg; -FHH = 37 ± 13 mmHg; p = 0.3) of MVC static handgrip were not different statistically between the two groups. However, H/La adults with +FHH indicated a trend for augmented pressor response during PEI following handgrip exercise at 40% of MVC (+FHH = 46 ± 4 mmHg; -FHH = 33 ± 10; p = 0.07). The cold pressor response was not different between the two groups (+FHH = 31 ± 6 mmHg; -FHH = 23 ± 15 mmHg; p = 0.36). CONCLUSION: Our preliminary data suggest that Hispanic adults with family history of hypertension exhibit augmented activation of muscle metaboreflex

Influence of Family History of Hypertension on Vascular Function in Young Healthy Black Women

Compared to all other racial groups, non-Hispanic Black (NHB) women have the highest prevalence of hypertension (58.4%) in the United States and experience a two-fold higher mortality from hypertension-related causes. Individuals with a positive family history of hypertension (+FHH) have been shown to exhibit blunted vascular function in response to 5-minute ischemia; however, whether the impact of positive family history of hypertension (+FHH) results in a greater attenuation of vascular function in healthy NHB women remains unknown. PURPOSE: Herein, we tested the hypothesis that young NHB women with +FHH will elicit attenuated increases in forearm blood flow (FBF) and forearm vascular conductance (FVC) during rhythmic handgrip exercise (RHG) compared to age- and weight-matched NHB women without a family history of hypertension (-FHH). METHODS: We studied 14 young normotensive women (+FHH=7) [Age (-FFH: 19 ± 1; and +FHH: 19 ± 1yr; mean ± SD, p = 0.61); BMI (-FFH: 24 ± 2; and +FFH: 24 ± 2 kg/m2; p = 0.82)]. FBF (duplex Doppler ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured during rhythmic handgrip exercise performed at three workloads (15%, 30%, and 45% of maximal voluntary contraction (MVC)). FVC was calculated as FBF/MAP. RESULTS: Baseline FBF (-FHH: 41.9 ± 14.0 and +FHH: 48.0 ± 7.1 ml/min; p = 0.32), FVC (-FHH: 50.0 ± 15.9 and +FHH: 62.9 ± 10.2 ml/min/100 mmHg; p = 0.10), and MVCs (-FHH: 57 ± 12 and +FHH: 54 ± 7 kg; p = 0.53) were similar between the groups. Both groups exhibited intensity-dependent increases in FBF and FVC; however, contrary to our hypothesis, there were no difference between the groups [mixed-model two-way ANOVA; %Δ FBF (group effect p = 0.50, intensity effect p \u3c 0.001, interaction p = 0.89) and %Δ FVC (group effect p = 0.34, intensity effect p \u3c 0.001, interaction p = 0.92). For instance, in response to RHG at 45%, -FHH had 592 ± 190 % increase in FBF from baseline and +FHH had 624 ± 154 % increase. Changes in MAP were not different between the groups at any intensity (e.g., ΔMAP at 45% MVC in -FHH = 11 ± 9 and +FHH = 6 ± 5, p = 0.30). CONCLUSION: These preliminary data suggest that the hyperemic responses to rhythmic handgrip exercise in normotensive Black women is not influenced by a positive family history of hypertension

Chinese Americans’ Views and Use of Family Health History: A Qualitative Study

Objective Family health history (FHH) plays a significant role in early disease detection and preven- tion. Although Asian Americans are the fastest growing U.S. immigrant group, no data exists regarding Chinese Americans’ (the largest Asian subgroup) views and use of FHH. This study examines this important issue. Methods Forty-nine adults from southern U.S. Chinese American communities participated in this qualitative, semi-structured, in-depth interview study. Interviews were audio recorded, tran- scribed, and analyzed with a content analysis approach. Results Although the majority of participants perceived the importance of collecting FHH, most lacked FHH knowledge and failed to collect FHH information. Barriers affecting FHH collec- tion and discussion among family members included long-distance separation from family members, self-defined “healthy family,� and Chinese cultural beliefs. Lack of doctors’ inqui- ries, never/rarely visiting physicians, self-defined “healthy family,� perceived insignificance of discussing FHH with doctors, and Chinese cultural beliefs were the obstacles in commu- nicating FHH with physicians. Conclusions Chinese Americans had limited usage of their FHH and faced cultural, distance, knowl- edge-, and healthcare system-related barriers that influenced their FHH use. Developing FHH education programs for Chinese Americans is highly recommended

Impaired autoregulation of renal blood flow in the fawn-hooded rat

The responses to changes in renal perfusion pressure (RPP) were compared in 12-wk-old fawn-hooded hypertensive (FHH), fawn-hooded low blood pressure (FHL), and August Copenhagen Irish (ACI) rats to determine whether autoregulation of renal blood flow (RBF) is altered in the FHH rat. Mean arterial pressure was significantly higher in conscious, chronically instrumented FHH rats than in FHL rats (121 +/- 4 vs. 109 +/- 6 mmHg). Baseline arterial pressures measured in ketamine-Inactin-anesthetized rats averaged 147 +/- 2 mmHg (n = 9) in FHH, 132 +/- 2 mmHg (n = 10) in FHL, and 123 +/- 4 mmHg (n = 9) in ACI rats. Baseline RBF was significantly higher in FHH than in FHL and ACI rats and averaged 9.6 +/- 0.7, 7.4 +/- 0.5, and 7.8 +/- 0.9 ml. min-1. g kidney wt-1, respectively. RBF was autoregulated in ACI and FHL but not in FHH rats. Autoregulatory indexes in the range of RPPs from 100 to 150 mmHg averaged 0.96 +/- 0.12 in FHH vs. 0.42 +/- 0.04 in FHL and 0.30 +/- 0.02 in ACI rats. Glomerular filtration rate was 20-30% higher in FHH than in FHL and ACI rats. Elevations in RPP from 100 to 150 mmHg increased urinary protein excretion in FHH rats from 27 +/- 2 to 87 +/- 3 microg/min, whereas it was not significantly altered in FHL or ACI rats. The percentage of glomeruli exhibiting histological evidence of injury was not significantly different in the three strains of rats. These results indicate that autoregulation of RBF is impaired in FHH rats before the development of glomerulosclerosis and suggest that an abnormality in the control of renal vascular resistance may contribute to the development of proteinuria and renal failure in this strain of rats

Clinical and outcome comparison of genetically positive vs. negative patients in a large cohort of suspected familial hypocalciuric hypercalcemia

Biochemical suspicion of familial hypocalciuric hypercalcemia (FHH) might provide with a negative (FHH-negative) or positive (FHH-positive) genetic result. Understanding the differences between both groups may refine the identification of those with a positive genetic evaluation, aid management decisions and prospective surveillance. We aimed to compare FHH-positive and FHH-negative patients, and to identify predictive variables for FHH-positive cases. Retrospective, national multi-centre study of patients with suspected FHH and genetic testing of the CASR, AP2S1 and GNA11 genes. Clinical, biochemical, radiological and treatment data were collected. We established a prediction model for the identification of FHH-positive cases by logistic regression analysis and area under the ROC curve (AUROC) was estimated. We included 66 index cases, of which 30 (45.5%) had a pathogenic variant. FHH-positive cases were younger (p = 0.029), reported more frequently a positive family history (p < 0.001), presented higher magnesium (p < 0.001) and lower parathormone levels (p < 0.001) and were less often treated for hypercalcemia (p = 0.017) in comparison to FHH-negative cases. Magnesium levels showed the highest AUROC (0.825, 95%CI: 0.709-0.941). The multivariate analysis revealed that family history and magnesium levels were independent predictors of a positive genetic result. The predictive model showed an AUROC of 0.909 (95%CI: 0.826-0.991). The combination of magnesium and a positive family history offered a good diagnostic accuracy to predict a positive genetic result. Therefore, the inclusion of magnesium measurement in the routine evaluation of patients with suspected FHH might provide insight into the identification of a positive genetic result of any of the CaSR-related genes

Transition from van-der-Waals to H Bonds dominated Interaction in n-Propanol physisorbed on Graphite

Multilayer sorption isotherms of 1-propanol on graphite have been measured by means of high-resolution ellipsometry within the liquid regime of the adsorbed film for temperatures ranging from 180 to 260 K. In the first three monolayers the molecules are oriented parallel to the substrate and the growth is roughly consistent with the Frenkel-Halsey-Hill-model (FHH) that is obeyed in van-der-Waals systems on strong substrates. The condensation of the fourth and higher layers is delayed with respect to the FHH-model. The fourth layer is actually a bilayer. Furthermore there is indication of a wetting transition. The results are interpreted in terms of hydrogen-bridge bonding within and between the layers.Comment: 4 pages, 3 figure

Determinants of Female-headed Households’ Livelihood Diversification Strategies Choice in Ambo District, Ethiopia

The study has concluded that diverse livelihood options are available and thus,Female - Headed Households pursue diverse range of activities that draw on their labor and time. However, the participation levels vary within Female - Headed Households(FHHs). The variation is mainly in terms of the activity they diversify into and conditions under which diversification are made. Generally, FHH participate in low-return and high risk and last resort activities. The study concludes that livelihood diversification strategies choice of FHH is determined by a number of factors. Hence, it is recommended that the livelihood of FHHs needs to be recognized and policy intervention should concentrate on improving access to assets within the aim of expanding livelihood options rather than assuming households are spatial homogenous and individual engage in one type of activity only

Disorders of the calcium-sensing receptor and partner proteins: insights into the molecular basis of calcium homeostasis

The extracellular calcium (Ca(2+)(o))-sensing receptor (CaSR) is a family C G protein-coupled receptor, which detects alterations in Ca(2+)(o) concentrations and modulates parathyroid hormone secretion and urinary calcium excretion. The central role of the CaSR in Ca(2+)(o) homeostasis has been highlighted by the identification of mutations affecting the CASR gene on chromosome 3q21.1. Loss-of-function CASR mutations cause familial hypocalciuric hypercalcaemia (FHH), whereas gain-of-function mutations lead to autosomal dominant hypocalcaemia (ADH). However, CASR mutations are only detected in ≤70% of FHH and ADH cases, referred to as FHH type 1 and ADH type 1, respectively, and studies in other FHH and ADH kindreds have revealed these disorders to be genetically heterogeneous. Thus, loss- and gain-of-function mutations of the GNA11 gene on chromosome 19p13.3, which encodes the G-protein α-11 (Gα(11)) subunit, lead to FHH type 2 and ADH type 2, respectively; whilst loss-of-function mutations of AP2S1 on chromosome 19q13.3, which encodes the adaptor-related protein complex 2 sigma (AP2σ) subunit, cause FHH type 3. These studies have demonstrated Gα(11) to be a key mediator of downstream CaSR signal transduction, and also revealed a role for AP2σ, which is involved in clathrin-mediated endocytosis, in CaSR signalling and trafficking. Moreover, FHH type 3 has been demonstrated to represent a more severe FHH variant that may lead to symptomatic hypercalcaemia, low bone mineral density and cognitive dysfunction. In addition, calcimimetic and calcilytic drugs, which are positive and negative CaSR allosteric modulators, respectively, have been shown to be of potential benefit for these FHH and ADH disorders