Sharp increase in gonorrhoea notifications among young people, EU/EEA, July 2022 to June 2023.

Gonorrhoea cases increased steeply in women aged 20 to 24 years across 15 EU/EEA countries in July to December 2022 and January to June 2023 with, respectively, 73% and 89% more cases reported than expected, based on historical data from 2015 to 2019. Smaller increases among men due to heterosexual transmission were observed in nine EU/EEA countries. Interventions to raise awareness among young people about sexually transmitted infection risks are needed, emphasising the benefit of safe sexual practices and testing.

Decline in varicella cases contacting primary health care after introduction of varicella vaccination in Finland - A population-based register study.

A two-dose varicella vaccination programme at the age of 18 months and 6 years started in September 2017 in Finland with catch-up vaccinations, based on earlier modelling results, for children <12 years (born in 2006 or later) with no history of varicella. Nationwide population-based register data were used to assess the age-specific vaccination coverage and the annual incidence rates of varicella cases contacting public primary health care in 2014-2020. Age-specific incidence rates after (2022) and before (2014-2016) the implementation of the vaccination programme was compared by incidence rate ratios (IRR) with 95 % confidence interval. In 2019-2022, the first-dose coverage of varicella vaccination among children following the routine vaccination programme ranged from 85 to 87 % (children born in 2016 or later). The second-dose coverage was 58 % for the children born in 2016. The coverage of the catch-up vaccinations ranged from 18 % (children born in 2006) to 82 % (children born in 2015) for the first dose and from 10 % to 64 % for the second dose in the respective birth cohorts. In 2022, compared to the pre-vaccination period (2014-2016) the annual incidence rate of varicella cases contacting public primary health care declined in all age groups. The reduction ranged from 92 % to 98 % among the children eligible for the vaccinations (born 2006 or later). The 87 % reduction in the incidence rate among the unvaccinated children < 1 year suggests the indirect effect of the vaccinations. Introducing varicella vaccinations with catch-up was associated with rapid reduction in the varicella cases contacting primary health care in all ages. However, the coverage of the routine programme needs to be improved further as presently susceptibles accumulate and enable thus further outbreaks in coming decades.

Risk of COVID-19 in different groups of healthcare professionals between February 2020 and June 2021 in Finland: a register-based cohort study.

Background: During the Coronavirus Disease 2019 (COVID-19) pandemic, healthcare workers (HCWs) have been a risk group for COVID-19. Aim: To assess the cumulative incidence in different groups of HCWs and the risk factors and outcomes of COVID-19 in HCWs between February 2020 and June 2021 in Finland. Methods: We linked two national registers, National Infectious Diseases Register (NIDR) and Register of Social Welfare and Healthcare Professionals (Terhikki), using national identity codes. COVID-19 cases were identified from NIDR notifications made by laboratories and physicians, and their healthcare professions from Terhikki. We categorized healthcare professions into seven groups and calculated cumulative incidences using Kaplan-Meier estimate during three periods (1/2/2020-30/6/2020, 1/7/2020-31/12/2020, 1/1/2021-30/6/2021). We identified risk factors in a multivariable model using Cox's regression. Findings: We identified 8,009 COVID-19-cases among HCWs, with cumulative incidence of 1.79%; 83% were female, median age was 40.9 years (interquartile range, 31.2-51.6). Most COVID-19-cases occurred in nursing assistants (53%) and nurses (17%), with the highest cumulative incidences 2.07% (95%CI, 2.01-2.13%) and 1.82% (95%CI, 1.73-1.91%), respectively. Risk factors were male sex (hazard ratio (HR) 1.2; 95%CI, 1.1-1.3), foreign native language (HR 2.5; 95%CI, 2.2-2.9) and foreign country of birth (HR 1.2; 95%CI, 1.1-1.4). Physician notification data was available for 6,113/8,009 cases (76.3%); 244/6,113 (4.0%) were hospitalized and 37/6,113 (0.6%) in intensive care. Conclusion: Nurses and nursing assistant, especially men and professionals with foreign background, were at higher risk of COVID-19. This should be specifically addressed during training and implementing infection control measures to protect themselves and patients.

Initial assessment of the COVID-19 vaccination's impact on case numbers, hospitalisations and deaths in people aged 80 years and older, 15 EU/EEA countries, December 2020 to May 2021.

Prioritisation of elderly people in COVID-19 vaccination campaigns aimed at reducing severe outcomes in this group. Using EU/EEA surveillance and vaccination uptake, we estimated the risk ratio of case, hospitalisation and death notifications in people 80 years and older compared with 25-59-year-olds. Highest impact was observed for full vaccination uptake 80% or higher with reductions in notification rates of cases up to 65% (IRR: 0.35; 95% CI: 0.13-0.99), hospitalisations up to 78% (IRR: 0.22; 95% CI: 0.13-0.37) and deaths up to 84% (IRR: 0.16; 95% CI: 0.13-0.20).

Recent establishment of tick-borne encephalitis foci with distinct viral lineages in the Helsinki area, Finland.

Number of tick-borne encephalitis (TBE) cases has increased and new foci have emerged in Finland during the last decade. We evaluated risk for locally acquired TBE in the capital region inhabited by 1.2 million people. We screened ticks and small mammals from probable places of TBE virus (TBEV) transmission and places without reported circulation. The TBEV positive samples were sequenced and subjected to phylogenetic analysis. Within the study period 2007-2017, there was a clear increase of both all TBE cases and locally acquired cases in the Helsinki area. The surveillance of ticks and small mammals for TBEV confirmed four distinct TBEV foci in the Helsinki area. All detected TBEV strains were of the European subtype. TBEV genome sequences indicated that distinct TBEV lineages circulate in each focus. Molecular clock analysis suggested that the virus lineages were introduced to these foci decades ago. In conclusion, TBE has emerged in the mainland of Helsinki area during the last decade, with at least four distinct virus lineages independently introduced into the region previously. Although the overall annual TBE incidence is below the threshold for recommending general vaccinations, the situation requires further surveillance to detect and prevent possible further emergence of local TBE clusters.

Decreased incidence of pertussis in young adults after the introduction of booster vaccine in military conscripts: Epidemiological analyses of pertussis in Finland, 1995-2015.

INTRODUCTION: In 2005, in Finland, the whole-cell pertussis vaccine was replaced by acellular given at 3-5-12months, and boosters at 4 and 11-15years of age. From July 2012, military conscripts have been offered a pertussis booster dose. Conscription is mandatory for Finnish men, and >95% were 19-21years old when enrolled during 2012-2015. We describe the epidemiology of pertussis in Finland during 1995-2015, and show the indirect effect of the booster in conscripts on pertussis incidence in the Finnish population. MATERIALS AND METHODS: We extracted data on laboratory confirmed notified pertussis cases from the National Infectious Diseases Register. We calculated annual incidence using as denominator population data and incidence rate ratios (IRR) using Poisson regression. RESULTS: The overall pertussis incidence peaked in 2004 (31/100,000) and was lowest in 2015 (3.0/100,000), with 66 reported cases in <3months infants in 2004 versus 6 in 2015. The majority of the cases were female (59%) with a male-to-female case ratio of 1:1.5. Cases were spread throughout the year with highest incidence during August-February. Among the 19- to 21-year-olds in the general population, incidence decreased from 49/100,000 in 2011 to 0.51/100,000 in 2015 (IRR=0.01; 95%CI, 0.00-0.16). Among the same age group, comparing the 3.5-year period before and after July 2012, incidence decreased from 33/100,000 to 5.3/100,000 (IRR=0.16; 95%CI, 0.06-0.40) in males and from 16/100,000 to 5.0/100,000 (IRR=0.31; 95%CI, 0.11-0.84) in females. CONCLUSIONS: Implementation of the pertussis booster dose in Finnish military conscripts was followed by a significant decrease in pertussis incidence both among the 19- to 21-year-old males and females, possibly reflecting herd immunity effect. Together with booster doses in adolescents this has resulted in low incidence in the whole population including infants. Our results support the implementation of the booster dose for conscripts. We recommend continuing monitoring pertussis epidemiology to optimize pertussis vaccination strategies in Finland.

Contamination by Norovirus and Adenovirus on Environmental Surfaces and in Hands of Conscripts in Two Finnish Garrisons.

This study investigated the presence of norovirus and adenovirus, especially enteric adenovirus, on the environmental surfaces (n = 481) and military conscripts' hands (n = 109) in two Finnish garrisons (A and B) in 2013 and 2014. A questionnaire study was conducted to reveal possible correlations between viral findings on the conscripts' hands and their acute gastroenteritis symptoms. In addition to the swab samples, 14 fecal samples were obtained for viral analysis. In total, norovirus was present in 9.0 % of the surface swabs in 2013, whereas enteric adenovirus was present in 0.0 % and non-enteric adenovirus in 9.4 %. In the same year, 2.6 % of the hand swabs contained norovirus, 2.6 % enteric adenovirus, and 40.3 % non-enteric adenovirus. Norovirus GI.6 was continually detected on the surfaces of garrison A, and identical virus was detected in some of the fecal samples. In garrison B, two slightly different norovirus GII.4 strains were present on the surfaces. The questionnaires revealed no recent acute gastroenteritis cases in garrison A, but in garrison B, where the norovirus-positive hand swabs were collected, 30.6 % of the conscripts reported of recent symptoms. In 2014, norovirus was rarely detected, but adenovirus was again frequently present, both on the surfaces and hands. Taken together, our results suggest that gastroenteritis outbreaks occurred in 2013, but not in 2014. Due to the low number of hand swabs positive for enteric viruses, no conclusions about associations between viral findings and gastroenteritis symptoms could be drawn. This study increased our understanding of the possible transmission of viruses via contaminated environment and hands.

STK39 variation predicts the ambulatory blood pressure response to losartan in hypertensive men.

Large-scale genome-wide association studies (GWASs) have identified significant associations of common genetic variants with blood pressure (BP) levels. To obtain more evidence for the role of these variants in BP regulation, we studied their association with BP responses to four different antihypertensive drug monotherapies. We selected 19 single-nucleotide variants based on data from five GWASs. The study group consisted of more than 200 hypertensive Finnish men from the GENRES study. Ambulatory BP responses to 4-week treatments with losartan, bisoprolol, hydrochlorothiazide and amlodipine were the primary targets of the study. Secondarily, baseline indicators of the activity of the renin-angiotensin-aldosterone system were studied. After correction for multiple comparisons, the variant rs6749447 in the STK39 gene was significantly associated with BP responses. Thus, the minor rs6749447 allele was associated with a lower systolic and diastolic BP response to losartan (P=0.0005 and 0.0002, respectively). rs6749447 minor allele homozygotes had marginally higher serum aldosterone/plasma renin activity (PRA) ratios (P=0.04) than those without this allele. In a replication study on aldosterone and renin levels, another cohort of hypertensive patients (n=311) showed a similar trend. When the two cohorts were combined, the aldosterone level (P=0.02) and the aldosterone/PRA ratio (P=0.01) were higher in subjects homozygous for the minor rs6749447 allele than in other subjects. The present study shows that pharmacogenetic approaches may provide evidence that complements systematic genome-wide strategies by identifying gene loci that not only affect the BP level but also might modify its response to pharmacologic interventions.

Plasmodium falciparum--malaria in pregnant African immigrants often goes unrecognized.

We report four cases of asymptomatic Plasmodium falciparum malaria in pregnant African women. They had immigrated to Finland 3 to 13 months earlier. The disease was revealed only by anemia. The diagnosis relied on blood smear which showed a parasitemia <0.2% in three cases. Medical personnel should be informed about the possibility of afebrile forms of malaria in pregnant women even months after immigration. Very low levels of parasitemia may call for a more sensitive diagnostic approach such as polymerase chain reaction.

Licorice-induced hypertension and common variants of genes regulating renal sodium reabsorption.

AIM: To study if gene alterations affecting renal sodium reabsorption associate with susceptibility to licorice-induced hypertension. METHODS: Finnish subjects (n = 30) with a previously documented incident of licorice-induced hypertension were recruited for the study using a newspaper announcement. Their previous clinical and family histories as well as serum electrolyte levels were examined. DNA samples from all individuals were screened for variants of the genes encoding 11beta-hydroxysteroid dehydrogenase type 2 (11betaHSD2) and alpha-, beta-, and gamma-subunits of the epithelial sodium channel (ENaC). RESULTS: Upon licorice predisposition, the patients had a mean blood pressure of 201/118 mmHg. Circulating potassium, renin, and aldosterone levels were low. No significant DNA variations were identified in the 11betaHSD2 gene. Four subjects were heterozygous for beta- and gammaENaC variants previously shown to be associated with hypertension. Furthermore, a novel G insertion (2004-2005insG) in the SCNN1A gene encoding the alphaENaC was identified in two subjects. The frequency of these ENaC variants was significantly higher in subjects with licorice-induced hypertension (6/30 i.e. 20%) than in blood donors (11/301 i.e. 3.7%, P = 0.002). CONCLUSIONS: Defects of the 11betaHSD2 gene do not constitute a likely cause for licorice-induced hypertension. Variants of the ENaC subunits may render some individuals sensitive to licorice-induced metabolic alterations and hypertension.

Common genetic variation of beta1- and beta2-adrenergic receptor and response to four classes of antihypertensive treatment.

Varying results have been reported on the association of beta-adrenergic receptor polymorphisms with blood pressure (BP) response to beta-blockers. We investigated the influence of ADRB1 Ser49Gly and Arg389Gly, and ADRB2 Gly16Arg and Glu27Gln polymorphisms on ambulatory BP response to bisoprolol and three other antihypertensive drug monotherapies in a placebo-controlled, double-blind, cross-over study with 233 moderately hypertensive men. ADRB1 Ser49Ser homozygotes tended to have a better ambulatory BP response to bisoprolol but the difference was statistically nonsignificant. ADRB1 Arg389Arg homozygotes did not show better BP response to bisoprolol than the other genotypes. There were no significant associations of ADRB2 polymorphisms with BP responses to any of the study drugs. The results from this controlled study in hypertensive men do not support clinical use of common polymorphisms in ADRB1 and ADRB2 in predicting BP responses to beta-blockers or to three other antihypertensive drugs.

Common genetic variations of the renin-angiotensin-aldosterone system and response to acute angiotensin I-converting enzyme inhibition in essential hypertension.

OBJECTIVE: In order to get insight into possible genetic determinants of antihypertensive drug action, we analysed the relations between polymorphisms of the genes of the renin-angiotensin-aldosterone system and acute effects of ACE inhibition on blood pressure as well as circulating renin and aldosterone levels in hypertensive patients. METHODS: A total of 315 hypertensive patients referred for problems in drug treatment were given a single 50 mg dose of captopril. Plasma renin and aldosterone were measured before and 60 min after the drug administration. Four DNA variants, including angiotensin type I receptor (AGTR1) 1166 A/C, angiotensin-converting enzyme (ACE) I/D, angiotensinogen (AGT) M235T and AGT -217 G/A, were genotyped in the patients and normotensive men (n = 175). A replication study on the relation between AGTR1 1166 A/C and plasma renin and aldosterone levels was carried out in the 244 hypertensive men of the pharmacogenetic GENRES Study. RESULTS: Referred hypertensive patients with the AGTR1 CC genotype had higher aldosterone at baseline (P = 0.02) and after 60 min of captopril administration (P = 0.01) compared with the AA genotype. Replicate analysis in the GENRES patients showed a similar trend. When the two studies were combined (315 and 244 patients, respectively), plasma aldosterone level (P = 0.007) as well as aldosterone/renin ratio (P = 0.04) were significantly higher in the CC genotype (n = 13) than in the AA genotype (n = 370). Transfection studies in cultured HEK293 cells indicated that the 1166C allele was associated with higher mRNA levels than the 1166A allele. CONCLUSION: The AGTR1 1166C allele when present in homozygous form may be associated with a form of essential hypertension characterized by high plasma aldosterone and low plasma renin levels, possibly due to increased AGTR1 mRNA levels and augmented angiotensin II action.

CYP2C9 genotype modifies activity of the renin-angiotensin-aldosterone system in hypertensive men.

BACKGROUND: Two variants of the CYP2C9 gene, CYP2C9*2 and CYP2C9*3, have been indicated to have impaired enzyme function, and thus suspected to reduce the formation of the active metabolite of losartan. Cytochrome P450 (CYP) enzymes are also involved in eicosanoid biosynthesis and regulation of blood pressure (BP) and sodium homeostasis. METHODS: We studied the impact of these variants on BP response to losartan and three other antihypertensive drugs and on baseline indicators of the activity of the renin-angiotensin-aldosterone system. The participants were 217 moderately hypertensive Finnish men that participated in the double-blind, cross-over, placebo-controlled GENRES Study. RESULTS: BP responses to losartan did not differ between CYP2C9*2 or CYP2C9*3 allele carriers and CYP2C9*1*1 patients. A suggestive finding of less pronounced ambulatory BP response to losartan in CYP2C9*1*3 patients with low-normal kidney function was made. At baseline of the GENRES Study, CYP2C9*1*3 patients had significantly lower plasma renin activity and aldosterone levels than CYP2C9*1*1 patients (both P values 0.004). In a replication study in patients with treatment-resistant hypertension, men with CYP2C9*3 allele also had lower plasma renin activity (P = 0.03) and aldosterone levels (P = 0.18). In addition, these men had attenuated renin and aldosterone responses in captopril challenge test (P = 0.29 and 0.006, respectively). CONCLUSION: The CYP2C9*3 allele was associated with lower activity of the renin-angiotensin-aldosterone system in hypertensive men, which may reflect a more efficient sodium reabsorption capacity. CYP2C9*2 and CYP2C9*3 alleles do not influence the antihypertensive effect of losartan in men with essential hypertension and normal kidney function.

Short-term electrophysiological effects of losartan, bisoprolol, amlodipine, and hydrochlorothiazide in hypertensive men.

BACKGROUND AND AIM: Hypertension-induced left ventricular structural remodelling associates with repolarization abnormalities. We investigated if antihypertensive drugs can modulate ventricular repolarization. METHODS: A total of 183 hypertensive men received for 4 weeks drugs (losartan 50 mg, bisoprolol 5 mg, amlodipine 5 mg, hydrochlorothiazide (HCTZ) 25 mg) in a randomized order, separated by 4-week placebo periods. Electrocardiograms (ECG) were recorded at the end of placebo and drug periods. Measurements of repolarization duration (QT intervals), repolarization heterogeneity (T-wave peak to T-wave end (TPE) intervals), and T-wave morphology (T-wave principal component analysis (PCA) ratio, T-wave morphology dispersion (TMD), and total cosine R-to-T (TCRT)) during each drug were compared to placebo measurements. RESULTS: Losartan and bisoprolol shortened maximum and mean rate-adjusted QT intervals as well as mean TPE interval, decreased TMD, and increased TCRT. Losartan also shortened precordial maximum TPE interval and decreased PCA ratio. Amlodipine had no repolarization effects, whereas HCTZ prolonged precordial maximum TPE interval and mean TPE interval. CONCLUSION: Losartan and bisoprolol have beneficial short-term ECG repolarization effects. Amlodipine seems to have no repolarization effects. HCTZ seems to prolong the ECG TPE interval, potentially reflecting increased repolarization heterogeneity. These findings show that antihypertensive drugs may relatively rapidly and treatment-specifically modulate ECG markers of ventricular repolarization.

Renin-angiotensin system and alpha-adducin gene polymorphisms and their relation to responses to antihypertensive drugs: results from the GENRES study.

BACKGROUND: Polymorphisms in genes coding for components of the renin-angiotensin system (RAS) and alpha-adducin (ADD1) have been reported to be associated with blood pressure (BP) responses to antihypertensive agents. The results, however, have not been consistent and most of the earlier studies have been small and lacked placebo-control. Therefore, the association of common polymorphisms in these genes with BP responses to four different antihypertensive drugs was analyzed in a controlled study. METHODS: The study included 208 hypertensive Finnish men from the GENRES study. All of them used amlodipine 5 mg, bisoprolol 5 mg, hydrochlorothiazide (HCT) 25 mg, and losartan 50 mg daily, each for 4 weeks as a monotherapy in a double-blind, randomized, study. The treatment periods were separated by 4-week placebo periods. Both 24-h ambulatory (ABP) and office BP (OBP) measurements were carried out. The polymorphisms analyzed were ADD1 Gly460Trp, angiotensinogen (AGT) Met235Thr, angiotensin converting enzyme (ACE) insertion/deletion (I/D), and angiotensin II type 1 receptor (AGTR1) 1166A/C. RESULTS: The presence of 460Trp allele of ADD1, previously suggested to be a marker of thiazide responsiveness, did not predict a better response to HCT. There was no significant association of AGT Met235Thr, ACE I/D, and AGTR1 1166A/C polymorphisms with BP responses to the study drugs. ADD1 460Trp and AGT 235Thr alleles were associated with higher systolic white coat effect (WCE) during the placebo periods (P values 0.03 and 0.01, respectively). CONCLUSIONS: Common polymorphisms of ADD1, AGT, ACE, and AGTR1 do not markedly predict BP responses to amlodipine, bisoprolol, HCT, and losartan, at least in white hypertensive men.

Laboratory tests as predictors of the antihypertensive effects of amlodipine, bisoprolol, hydrochlorothiazide and losartan in men: results from the randomized, double-blind, crossover GENRES Study.

OBJECTIVE: Individual blood pressure responses to antihypertensive therapy are difficult to predict. To improve optimization of antihypertensive therapy, we analyzed correlations of relevant laboratory tests with blood pressure responses to four antihypertensive monotherapies. METHODS: In the GENRES study, 208 Finnish men aged 35-60 years with moderate hypertension used amlodipine 5 mg, bisoprolol 5 mg, hydrochlorothiazide 25 mg and losartan 50 mg daily, each for 4 weeks as a monotherapy in a double-blind, randomized, placebo-controlled crossover study; that is, each subject received each type of monotherapy in a random order. The treatment periods were preceded and separated by 4-week placebo periods. Ambulatory 24-h and office blood pressure measurements were carried out after all study periods. Data from several biochemical tests were correlated to antihypertensive drug responses. RESULTS: Serum total calcium concentration was negatively correlated with blood pressure responses to amlodipine (P values 0.001-0.002). Plasma renin activity was positively correlated with blood pressure responses to losartan (P values 0.001-0.005) and bisoprolol (P values 0.03-0.17), and negatively with blood pressure responses to hydrochlorothiazide (P values 0.01-0.07). Daily urinary excretion of sodium was negatively correlated with ambulatory blood pressure responses to amlodipine (P values 0.001-0.01). CONCLUSIONS: In this carefully controlled study, marked individual variations in antihypertensive drug responsiveness were found to correlate to several baseline laboratory parameters. The negative correlation between serum calcium levels and amlodipine responses is intriguing and suggests an underlying mechanistic association. Collectively, our data imply that laboratory tests may have some value in prediction of the efficacy of various antihypertensive drug therapies, although great patient-to-patient variation remains an obstacle for exact predictive classification.

Relationship of electrocardiographic repolarization measures to echocardiographic left ventricular mass in men with hypertension.

OBJECTIVE: Arterial hypertension often leads to an increase in left ventricular mass (LVM). Marked left ventricular hypertrophy (LVH) is associated with potentially arrhythmogenic ventricular repolarization abnormalities, which may contribute to the increased risk of sudden cardiac death in this disorder. We studied whether electrocardiographic repolarization changes are already detectable in mild LVM increase associated with hypertension. METHODS: In 220 men (mean age 51+/-6 years) attending the GENRES hypertension study, we measured QT intervals (QTend and QTpeak), T-wave peak to T-wave end (TPE) intervals, and novel T-wave morphology parameters (principal component analysis ratio, T-wave morphology dispersion, total cosine R-to-T, and T-wave residuum) from a digital standard 12-lead electrocardiogram, and related them to echocardiographically determined LVM. RESULTS: In this group of moderately hypertensive men, the mean LVM index (LVMI; LVM divided by body surface area) was 99+/-19 g/m2, with only 18% of the subjects showing evidence of echocardiographic LVH (LVMI>116 g/m2). LVMI correlated significantly with QT intervals (r=0.16-0.21, P=0.018-0.002), TPE intervals (r=0.23-0.27, P<0.001), and T-wave morphology parameters (r=0.22-0.39, P<0.001). Except for the QTpeak interval, the relationship between LVMI and electrocardiographic repolarization parameters was independent in multivariate analyses. CONCLUSION: Altered electrocardiographic ventricular repolarization, indicating reduced repolarization reserve and possibly increased repolarization heterogeneity, is already present in hypertensive men with only mild LVM increase. At a population level, this may carry important risk implications for the large group of hypertensive patients.

Predictors of antihypertensive drug responses: initial data from a placebo-controlled, randomized, cross-over study with four antihypertensive drugs (The GENRES Study).

BACKGROUND: Only a minority of hypertensive individuals is adequately controlled for their hypertension, partially because reliable predictors for efficient antihypertensive drug therapy are lacking. METHODS: In a prospective, randomized, double-blind, cross-over, placebo-controlled study (The GENRES Study), 208 moderately hypertensive Finnish men (aged 35 to 60 years) were treated for 4 weeks with antihypertensive drugs from four different classes: amlodipine (5 mg), bisoprolol (5 mg), hydrochlorothiazide (25 mg), or losartan (50 mg) daily. Each individual received each of the four monotherapies in a randomized order. Four-week placebo periods were included before and between drug treatment periods. Antihypertensive responses were assessed with 24-h ambulatory and office measurements and analyzed according to age, body mass index, triceps skin fold thickness, waist-to-hip ratio, duration of hypertension, number of previous antihypertensive drugs, number of affected parents, and blood pressure (BP) levels, and profiles during placebo periods. RESULTS: The median BP responses in 24-h ambulatory recordings (systolic/diastolic) were 11/8 mm Hg for bisoprolol, 9/6 mm Hg for losartan, 7/5 mm Hg for amlodipine, and 5/2 mm Hg for hydrochlorothiazide. The highest pairwise within-subject correlations in BP responses were seen for the combinations of bisoprolol-losartan and amlodipine-hydrochlorothiazide. The BP responses to bisoprolol and losartan did not vary according to the variables. Amlodipine and hydrochlorothiazide responses were positively correlated with age, placebo BP level, and lower night-time dipping on placebo. CONCLUSIONS: Baseline clinical and BP parameters may be used to predict the efficacy of antihypertensive therapies. The GENRES Study material should provide an excellent platform for future pharmacogenetic analyses of antihypertensive drug responsiveness.

Common variants of the beta and gamma subunits of the epithelial sodium channel and their relation to plasma renin and aldosterone levels in essential hypertension.

BACKGROUND: Rare mutations of the epithelial sodium channel (ENaC) result in the monogenic hypertension form of Liddle's syndrome. We decided to screen for common variants in the ENaC beta and gamma subunits in patients with essential hypertension and to relate their occurrence to the activity of circulating renin-angiotensin-aldosterone system. METHODS: Initially, DNA samples from 27 patients with low renin/low aldosterone hypertension were examined. The DNA variants were subsequently screened for in 347 patients with treatment-resistant hypertension, 175 male subjects with documented long-lasting normotension and 301 healthy Plasma renin and aldosterone levels were measured under baseline conditions and during postural and captopril challenge tests. RESULTS: Two commonly occurring betaENaC variants (G589S and a novel intronic i12-17CT substitution) and one novel gammaENaC variant (V546I) were detected. One of these variants occurred in a heterozygous form in 32 patients, a prevalence (9.2%) significantly higher than that in normotensive males (2.9%, p = 0.007) and blood donors (3.0%, p = 0.001). betaENaC i12-17CT was significantly more prevalent in the hypertension group than in the two control groups combined (4.6% vs. 1.1%, p = 0.001). When expressed in Xenopus oocytes, neither of the two ENaC amino acid-changing variants showed a significant difference in activity compared with ENaC wild-type. No direct evidence for a mRNA splicing defect could be obtained for the betaENaC intronic variant. The ratio of daily urinary potassium excretion to upright and mean (of supine and upright values) plasma renin activity was higher in variant allele carriers than in non-carriers (p = 0.034 and p = 0.048). CONCLUSIONS: At least 9% of Finnish patients with hypertension admitted to a specialized center carry genetic variants of beta and gammaENaC, a three times higher prevalence than in the normotensive individuals or in random healthy controls. Patients with the variant alleles showed an increased urinary potassium excretion rate in relation to their renin levels.

Liddle's syndrome associated with a point mutation in the extracellular domain of the epithelial sodium channel gamma subunit.

OBJECTIVE: To characterize novel type of mutations of the epithelial sodium channel (ENaC) or subunits in patients with Liddle's syndrome, an autosomal dominant form of hypertension. PATIENTS AND METHODS: DNA samples from two probands with early-onset, treatment-resistant hypertension and suppressed plasma renin activity were initially screened for mutations in the C-terminal exons of the ENaC or subunit genes, using amplification by polymerase chain reaction and direct DNA sequencing. RESULTS: Two novel mutations causing Liddle's syndrome were identified. One mutation due to a single nucleotide insertion in the exon 13 of ENaC results in a frameshift at codon 601 and abrogates the PY motif similar to all the previously described ENaC mutations causing Liddle's syndrome. The other mutation, substituting serine for asparagine at codon 530 (Asn530Ser) of the extracellular loop of ENaC subunit, was found in a 25-year-old man with hypertension, hypokalemia, low plasma renin activity and low serum aldosterone levels. Hypertension and hypokalemia favorably responded to amiloride or triamterene administration both in the proband and his affected mother. Expression of the mutant Asn530Ser ENaC subunit in oocytes demonstrated a two-fold increase in ENaC activity, compared with the wild-type, without a significant change in cell surface expression of ENaC. This suggests that the gammaENaC Asn530Ser mutation increases the channel open probability, and is consistent with an abnormally high sodium reabsorption in the distal nephron. CONCLUSIONS: This study describes the first mutation located in the extracellular domain of an ENaC subunit associated with an increased ENaC activity and Liddle's syndrome.