Objetivo: Investigar o efeito de se distinguir a pressão arterial noturna da pressão arterial no sono pelo registro simultâneo da monitorização ambulatorial da pressão arterial e da polissonografia. Métodos: Recrutaram-se 36 pacientes, 29 homens e 7 mulheres, com suspeita de síndrome das apnéias e hipopnéias obstrutivas do sono (SAHOS), encaminhados à clínica do sono para investigação diagnóstica e que concordaram usar o monitor ambulatorial de pressão arterial (MAPA) Spacelabs 90207 ABP durante a polissonografia (PSG). A média de idade dos indivíduos era 45 ± 11 anos; o índice de massa corporal (IMC), 30,8 ± 5,4 Kg/m2; o índice de apnéias e hipopnéias, 35 ± 29 AH/h. Um microfone acoplado ao monitor ambulatorial de PA registrou os sons característicos de sua atividade em um canal da polissonografia e permitiu determinar, de modo eletrográfico, se a PA foi medida em sono (e-sono) ou vigília (e-vigília).Resultados: Os pacientes encontravam-se dormindo durante (média+DP) 61+24% (variando de 0 a 100%), das 14+1 medidas de pressão arterial durante a noite. Leituras de pressão sistólica e diastólica na MAPA foram significativamente maiores durante o evigília (121 + 12 / 73 + 9 mm Hg) que durante o total do período noturno (119 + 11 / 70 + 8 mmHg) e e-sono (116 + 13 / 68 + 9 mm Hg). Baseado nas medidas do período noturno, 22 pacientes (61%) tinham hipertensão noturna; baseado nas medidas do período de e-sono, 12 pacientes tinham hipertensão noturna (33%; qui-quadrado= 5,54; p= 0,018). Um modelo de regressão linear múltipla mostrou que a percentagem de medidas feitas durante o e-sono foi a única variável que explicou significantemente a diferença entre os valores de PA noturna e PA em e-sono, controlando para gênero, idade, IMC, IAH, e SaO2 mínima. Conclusão: Durante a MAPA as leituras de PA noturnas são mais altas que as leituras durante e-sono. / Objective: Investigate the effect of distinguishing nighttime and sleep on nocturnal blood pressure results in ambulatory blood pressure monitoring (ABPM). Methods: We recruited 36 patients, 28 male, with suspected OSAHS attending a sleep clinic for diagnostic polysomnography (PSG) and who agreed to wear a Spacelabs 90207 ABP monitor during PSG. Their mean age was 45±11 years; body mass index (BMI), 30.8±5.4 kg/m2; apnea-hypopnea index (AHI), 35±29 AH/h; 13 had history of hypertension. A microphone attached to the ABP monitor recorded its sounds in the polygraph and allowed to classify each ABPM measurement as being made in electrographically-determined wake (e-wake) or sleep state (e-sleep). Results: Patients were asleep during (mean±SD) 61±24% (range 0 to 100%) of the 14±1 nighttime BP measurements. Systolic and diastolic ABPM readings were significantly higher during e-wake (121±12 / 73±9 mm Hg) than during total nighttime (119±11/70±8 m Hg) and e-sleep (116±13 / 68±9 mm Hg). Based on nighttime measurements 22 patients (61%) had nocturnal hypertension. Based on measurements made during e-sleep, nocturnal hypertension was diagnosed in 12 patients (33%; chisquare= 5.54; p= 0.018). A multiple linear regression model showed that the percentage of measurements made in e-sleep was the only variable that significantly explained the difference between nighttime and e-sleep BP figures, when controlling for gender, age, BMI, AHI, and lowest SaO2. Conclusion: During ABPM, nighttime BP readings are higher than during e-sleep and this changes dipping and nocturnal hypertension classification.

Objetivo: Investigar o efeito de se distinguir a pressão arterial noturna da pressão arterial no sono pelo registro simultâneo da monitorização ambulatorial da pressão arterial e da polissonografia. Métodos: Recrutaram-se 36 pacientes, 29 homens e 7 mulheres, com suspeita de síndrome das apnéias e hipopnéias obstrutivas do sono (SAHOS), encaminhados à clínica do sono para investigação diagnóstica e que concordaram usar o monitor ambulatorial de pressão arterial (MAPA) Spacelabs 90207 ABP durante a polissonografia (PSG). A média de idade dos indivíduos era 45 ± 11 anos; o índice de massa corporal (IMC), 30,8 ± 5,4 Kg/m2; o índice de apnéias e hipopnéias, 35 ± 29 AH/h. Um microfone acoplado ao monitor ambulatorial de PA registrou os sons característicos de sua atividade em um canal da polissonografia e permitiu determinar, de modo eletrográfico, se a PA foi medida em sono (e-sono) ou vigília (e-vigília).Resultados: Os pacientes encontravam-se dormindo durante (média+DP) 61+24% (variando de 0 a 100%), das 14+1 medidas de pressão arterial durante a noite. Leituras de pressão sistólica e diastólica na MAPA foram significativamente maiores durante o evigília (121 + 12 / 73 + 9 mm Hg) que durante o total do período noturno (119 + 11 / 70 + 8 mmHg) e e-sono (116 + 13 / 68 + 9 mm Hg). Baseado nas medidas do período noturno, 22 pacientes (61%) tinham hipertensão noturna; baseado nas medidas do período de e-sono, 12 pacientes tinham hipertensão noturna (33%; qui-quadrado= 5,54; p= 0,018). Um modelo de regressão linear múltipla mostrou que a percentagem de medidas feitas durante o e-sono foi a única variável que explicou significantemente a diferença entre os valores de PA noturna e PA em e-sono, controlando para gênero, idade, IMC, IAH, e SaO2 mínima. Conclusão: Durante a MAPA as leituras de PA noturnas são mais altas que as leituras durante e-sono. / Objective: Investigate the effect of distinguishing nighttime and sleep on nocturnal blood pressure results in ambulatory blood pressure monitoring (ABPM). Methods: We recruited 36 patients, 28 male, with suspected OSAHS attending a sleep clinic for diagnostic polysomnography (PSG) and who agreed to wear a Spacelabs 90207 ABP monitor during PSG. Their mean age was 45±11 years; body mass index (BMI), 30.8±5.4 kg/m2; apnea-hypopnea index (AHI), 35±29 AH/h; 13 had history of hypertension. A microphone attached to the ABP monitor recorded its sounds in the polygraph and allowed to classify each ABPM measurement as being made in electrographically-determined wake (e-wake) or sleep state (e-sleep). Results: Patients were asleep during (mean±SD) 61±24% (range 0 to 100%) of the 14±1 nighttime BP measurements. Systolic and diastolic ABPM readings were significantly higher during e-wake (121±12 / 73±9 mm Hg) than during total nighttime (119±11/70±8 m Hg) and e-sleep (116±13 / 68±9 mm Hg). Based on nighttime measurements 22 patients (61%) had nocturnal hypertension. Based on measurements made during e-sleep, nocturnal hypertension was diagnosed in 12 patients (33%; chisquare= 5.54; p= 0.018). A multiple linear regression model showed that the percentage of measurements made in e-sleep was the only variable that significantly explained the difference between nighttime and e-sleep BP figures, when controlling for gender, age, BMI, AHI, and lowest SaO2. Conclusion: During ABPM, nighttime BP readings are higher than during e-sleep and this changes dipping and nocturnal hypertension classification.

Objetivo: Investigar o efeito de se distinguir a pressão arterial noturna da pressão arterial no sono pelo registro simultâneo da monitorização ambulatorial da pressão arterial e da polissonografia. Métodos: Recrutaram-se 36 pacientes, 29 homens e 7 mulheres, com suspeita de síndrome das apnéias e hipopnéias obstrutivas do sono (SAHOS), encaminhados à clínica do sono para investigação diagnóstica e que concordaram usar o monitor ambulatorial de pressão arterial (MAPA) Spacelabs 90207 ABP durante a polissonografia (PSG). A média de idade dos indivíduos era 45 ± 11 anos; o índice de massa corporal (IMC), 30,8 ± 5,4 Kg/m2; o índice de apnéias e hipopnéias, 35 ± 29 AH/h. Um microfone acoplado ao monitor ambulatorial de PA registrou os sons característicos de sua atividade em um canal da polissonografia e permitiu determinar, de modo eletrográfico, se a PA foi medida em sono (e-sono) ou vigília (e-vigília).Resultados: Os pacientes encontravam-se dormindo durante (média+DP) 61+24% (variando de 0 a 100%), das 14+1 medidas de pressão arterial durante a noite. Leituras de pressão sistólica e diastólica na MAPA foram significativamente maiores durante o evigília (121 + 12 / 73 + 9 mm Hg) que durante o total do período noturno (119 + 11 / 70 + 8 mmHg) e e-sono (116 + 13 / 68 + 9 mm Hg). Baseado nas medidas do período noturno, 22 pacientes (61%) tinham hipertensão noturna; baseado nas medidas do período de e-sono, 12 pacientes tinham hipertensão noturna (33%; qui-quadrado= 5,54; p= 0,018). Um modelo de regressão linear múltipla mostrou que a percentagem de medidas feitas durante o e-sono foi a única variável que explicou significantemente a diferença entre os valores de PA noturna e PA em e-sono, controlando para gênero, idade, IMC, IAH, e SaO2 mínima. Conclusão: Durante a MAPA as leituras de PA noturnas são mais altas que as leituras durante e-sono. / Objective: Investigate the effect of distinguishing nighttime and sleep on nocturnal blood pressure results in ambulatory blood pressure monitoring (ABPM). Methods: We recruited 36 patients, 28 male, with suspected OSAHS attending a sleep clinic for diagnostic polysomnography (PSG) and who agreed to wear a Spacelabs 90207 ABP monitor during PSG. Their mean age was 45±11 years; body mass index (BMI), 30.8±5.4 kg/m2; apnea-hypopnea index (AHI), 35±29 AH/h; 13 had history of hypertension. A microphone attached to the ABP monitor recorded its sounds in the polygraph and allowed to classify each ABPM measurement as being made in electrographically-determined wake (e-wake) or sleep state (e-sleep). Results: Patients were asleep during (mean±SD) 61±24% (range 0 to 100%) of the 14±1 nighttime BP measurements. Systolic and diastolic ABPM readings were significantly higher during e-wake (121±12 / 73±9 mm Hg) than during total nighttime (119±11/70±8 m Hg) and e-sleep (116±13 / 68±9 mm Hg). Based on nighttime measurements 22 patients (61%) had nocturnal hypertension. Based on measurements made during e-sleep, nocturnal hypertension was diagnosed in 12 patients (33%; chisquare= 5.54; p= 0.018). A multiple linear regression model showed that the percentage of measurements made in e-sleep was the only variable that significantly explained the difference between nighttime and e-sleep BP figures, when controlling for gender, age, BMI, AHI, and lowest SaO2. Conclusion: During ABPM, nighttime BP readings are higher than during e-sleep and this changes dipping and nocturnal hypertension classification.

Motivation Hypertension and type 2 diabetes mellitus are common in the black population of South Africa. The literature also shows that elevated blood glucose concentrations can lead to an increase in blood pressure and a blunted decline in nocturnal blood pressure. Therefore, the motivation for this study was to determine if blood glucose may play a role regarding the blunted nocturnal decline in blood pressure in African and Caucasian men. Aim The aim of this study was to investigate the relationship between a blunted nocturnal decline in blood pressure and blood glucose in African and Caucasian men. Methodology A comparative population study was preformed that consisted of 202 school teachers (101 African and 101 Caucasian) between the ages of 25–60 years from the North West Province, South Africa. Subjects were excluded if their body temperature was elevated, had a dependence or abuse of psychotropic substances, were regular blood donors and/or vaccinated in the previous three months. Ambulatory systolic (SBP) and diastolic blood pressure (DBP) were measured. Blood samples from the antebrachial vein were collected in sodium fluoride tubes to determine the serum glucose level and glycosylated hemoglobin A1c (HbA1c) percentage. Estimated average glucose (eAG) was determined from the percentage HbA1c by means of a regression formula. Means and proportions were compared by standard t–test and the chi–square test, respectively. Pearson correlations were used to determine unadjusted associations and multiple regression analysis to determine adjusted associations between variables. Results and Conclusion African men had an elevated HbA1c (p<0.001), eAG (p<0.001), nighttime SBP (p<0.001) and DBP (p<0.001). These results remained similar when non–dipping African and Caucasian men were compared. The Africans also smoked more (p=0.012), consumed more alcohol (p=0.049), had a higher percentage of non–dippers (p=0.054), HIV infected subjects (p<0.001) and a larger number of subjects that used anti–hypertensive medication (p=0.049). The unadjusted analysis showed positive correlations between all the blood pressure measurements and serum glucose, HbA1c and eAG in the African non–dipper men. While in the non–dipper Caucasian men, only daytime SBP and nighttime SBP (22:00–06:00) correlated positively with serum glucose, HbA1c and eAG. Furthermore, when viewing the relationship between carotid intima–media thickness (CIMT) and the blood pressure measurements in the African population, only nighttime (00:00– 04:00) SBP (r=0.581, p<0.001) and DBP (r=0.566, p<0.001) showed positive associations. After adjustments were made for age and body mass index the associations between the various blood pressure measurements and blood glucose disappeared in the non–dipper Caucasian men. However, in the non–dipper African men both nighttime (22:00–06:00) SBP and (00:00– 04:00) SBP showed positive correlations with serum glucose, HbA1c and eAG. After full adjustments (age, BMI, smoking, alcohol intake, physical activity, C–reactive protein and baroreceptor sensitivity) were made, nighttime (00:00–04:00) SBP was the only measure of blood pressure that correlated positively with HbA1c (p=0.069) and eAG (p<0.001) in the nondipper African men. No significant relationships were found for Caucasian men. Furthermore, to determine if the association between nighttime (00:00–04:00) SBP and eAG were independent of CIMT, we adjusted for CIMT. By doing so the positive association between SBP and eAG remained significant in the non–dipper African men (R2=0.617; =0.438; p=0.008) and nonsignificant in the non–dipper Caucasian men (R2=0.423; =0.169; p=0.33). However, the relationship between CIMT and eAG disappeared when we adjusted for SBP, suggesting that the SBP and eAG relationship drives CIMT. In conclusion, the association between the early morning SBP (00:00–04:00) and the blood glucose in non–dipping African men suggests that the blunted decline in nocturnal blood pressure during the early morning hours is associated with chronically elevated blood glucose. / Thesis (M.Sc. (Physiology))--North-West University, Potchefstroom Campus, 2011.

Motivation Hypertension and type 2 diabetes mellitus are common in the black population of South Africa. The literature also shows that elevated blood glucose concentrations can lead to an increase in blood pressure and a blunted decline in nocturnal blood pressure. Therefore, the motivation for this study was to determine if blood glucose may play a role regarding the blunted nocturnal decline in blood pressure in African and Caucasian men. Aim The aim of this study was to investigate the relationship between a blunted nocturnal decline in blood pressure and blood glucose in African and Caucasian men. Methodology A comparative population study was preformed that consisted of 202 school teachers (101 African and 101 Caucasian) between the ages of 25–60 years from the North West Province, South Africa. Subjects were excluded if their body temperature was elevated, had a dependence or abuse of psychotropic substances, were regular blood donors and/or vaccinated in the previous three months. Ambulatory systolic (SBP) and diastolic blood pressure (DBP) were measured. Blood samples from the antebrachial vein were collected in sodium fluoride tubes to determine the serum glucose level and glycosylated hemoglobin A1c (HbA1c) percentage. Estimated average glucose (eAG) was determined from the percentage HbA1c by means of a regression formula. Means and proportions were compared by standard t–test and the chi–square test, respectively. Pearson correlations were used to determine unadjusted associations and multiple regression analysis to determine adjusted associations between variables. Results and Conclusion African men had an elevated HbA1c (p<0.001), eAG (p<0.001), nighttime SBP (p<0.001) and DBP (p<0.001). These results remained similar when non–dipping African and Caucasian men were compared. The Africans also smoked more (p=0.012), consumed more alcohol (p=0.049), had a higher percentage of non–dippers (p=0.054), HIV infected subjects (p<0.001) and a larger number of subjects that used anti–hypertensive medication (p=0.049). The unadjusted analysis showed positive correlations between all the blood pressure measurements and serum glucose, HbA1c and eAG in the African non–dipper men. While in the non–dipper Caucasian men, only daytime SBP and nighttime SBP (22:00–06:00) correlated positively with serum glucose, HbA1c and eAG. Furthermore, when viewing the relationship between carotid intima–media thickness (CIMT) and the blood pressure measurements in the African population, only nighttime (00:00– 04:00) SBP (r=0.581, p<0.001) and DBP (r=0.566, p<0.001) showed positive associations. After adjustments were made for age and body mass index the associations between the various blood pressure measurements and blood glucose disappeared in the non–dipper Caucasian men. However, in the non–dipper African men both nighttime (22:00–06:00) SBP and (00:00– 04:00) SBP showed positive correlations with serum glucose, HbA1c and eAG. After full adjustments (age, BMI, smoking, alcohol intake, physical activity, C–reactive protein and baroreceptor sensitivity) were made, nighttime (00:00–04:00) SBP was the only measure of blood pressure that correlated positively with HbA1c (p=0.069) and eAG (p<0.001) in the nondipper African men. No significant relationships were found for Caucasian men. Furthermore, to determine if the association between nighttime (00:00–04:00) SBP and eAG were independent of CIMT, we adjusted for CIMT. By doing so the positive association between SBP and eAG remained significant in the non–dipper African men (R2=0.617; =0.438; p=0.008) and nonsignificant in the non–dipper Caucasian men (R2=0.423; =0.169; p=0.33). However, the relationship between CIMT and eAG disappeared when we adjusted for SBP, suggesting that the SBP and eAG relationship drives CIMT. In conclusion, the association between the early morning SBP (00:00–04:00) and the blood glucose in non–dipping African men suggests that the blunted decline in nocturnal blood pressure during the early morning hours is associated with chronically elevated blood glucose. / Thesis (M.Sc. (Physiology))--North-West University, Potchefstroom Campus, 2011.