In this study, we recruited 5830 women participants of Hoveyzeh Cohort Study .The mean ± SD age at menarche in our study was 12.60 ± 1.76 years old .Mean age at menarche differed in Urban and rural women (at ages 12.58±1.71 and 12.63±1.83 years, respectively). Based on wealth index, the prevalence of early age of menarche (≤ 10 years) in poorest groups more than richest groups (26.1% vs. 11.1%). The overall prevalence of MetS in the enrollment phase in women 35-70 years in Hoveyzeh cohort study was 45.62% (25). The characteristics of women with or without Mets were reported in Table 1. Participants with MetS were older than without MetS group. Women with MetS had a less than mean age at menarche and HDL level. Controversy women with MetS had a greater mean BMI, height, weight, waist circumference, hip circumference, SBP, DBP, PR, TC, TG, FBS, ALK, AST, ALT levels.The results of the Chi-square test showed that there was a significant relationship between the variables of Wealth index, Use Alcohol, Smoker, Education, Contraceptive use ,and metabolic syndrome (P <0.0001). Also the results demonstrated that the difference between mean age of menarche and mean weight, Waist circumference, Hip circumference, Wrist circumference, SBP, DBP, PR, TC, TG, FBS, ALK, AST, ALT, Gravity, Parity in two groups with and without Metabolic syndrome was significant (P <0.0001). (Table1)
Table 1: Characteristics of study population by metabolic syndrome
Variables
|
Cases(n=2660)
|
Controls(n=3170)
|
P_value
|
Age, (years)
|
51.12 ± 9.17
|
46.28 ± 8.54
|
<0.001*
|
Age at menarche , (years)
|
12.51 ± 1.78
|
12.67 ± 1.74
|
<0.001*
|
Height, (cm)
|
158.97 ± 5.66
|
158.77 ± 5.68
|
0.18*
|
Weight, (kg)
|
78.87 ± 13.95
|
72.00 ± 15.11
|
<0.001*
|
BMI, (kg/m2)
|
31.18 ± 5.31
|
28.52 ± 5.60
|
<0.001*
|
Waist circumference, (cm)
|
105.67 ± 10.33
|
97.73 ± 12.28
|
<0.001*
|
Hip circumference, (cm)
|
107.90 ± 10.07
|
104.89 ± 10.33
|
<0.001*
|
Wrist circumference, (cm)
|
17.47 ± 1.34
|
16.93 ± 1.29
|
<0.001*
|
SBP, (mm Hg)
|
116.43 ± 20.06
|
106.08 ± 15.53
|
<0.001*
|
DBP, (mm Hg )
|
72.59 ± 11.42
|
67.82 ± 10.02
|
<0.001*
|
PR
|
80.47 ± 9.66
|
78.78 ± 9.27
|
<0.001*
|
FBS, (mg/dL)
|
130.61 ± 60.75
|
96.37 ± 28.98
|
<0.001*
|
HDL-C, (mg/dL)
|
48.21 ± 10.93
|
57.17 ± 11.82
|
<0.001*
|
TG, (mg/dL)
|
197.47 ± 103.05
|
111.57 ± 46.97
|
<0.001*
|
TC, (mg/dL)
|
195.74 ± 43.31
|
186.93 ± 37.93
|
<0.001*
|
AST
|
17.79 ± 11.32
|
17.22 ± 7.71
|
0.02*
|
ALT
|
19.21 ± 12.67
|
16.76 ± 11.54
|
<0.001
|
ALK
|
224.87 ± 65.71
|
197.64 ± 63.41
|
<0.001*
|
Gravity
|
6.64 ± 3.15
|
5.70 ± 2.87
|
<0.001*
|
Parity
|
6.07 ± 2.70
|
5.24 ± 2.47
|
<0.001*
|
Wealth index
|
poorest
|
568 (21.35)
|
740 (23.34)
|
0.002**
|
poor
|
529 (19.89)
|
736 (23.21)
|
moderate
|
546 (20.53)
|
587 (18.52)
|
rich
|
537 (20.19)
|
586 (18.48)
|
richest
|
480 (18.04)
|
521 (16.43)
|
Use Alcohol
|
Yes
|
4 (0.15)
|
2 (0.06)
|
0.30**
|
No
|
2656 (99.85)
|
3168 (99.94)
|
Smoker
|
Yes
|
228 (8.57)
|
206 (6.50)
|
0.003**
|
No
|
2432 (91.43)
|
2964 (93.50)
|
Education
|
Illiterate
|
2132 (80.15)
|
2324 (73.31)
|
<0.001**
|
Primary school
|
333 (12.52)
|
471 (14.86)
|
Secondary school
|
73 (2.74)
|
133 (4.20)
|
Diploma
|
74 (2.79)
|
124 (3.91)
|
University
|
48 (1.80)
|
118 (3.72)
|
Use Contraceptive
|
Yes
|
1582 (59.47)
|
1987 (62.68)
|
0.01**
|
No
|
1078 (40.53)
|
1183 (37.32)
|
*Independent T -test
**Chi-square test
Abbreviations
MetS: Metabolic Syndrome,T2D: Type 2 diabetes,TG: Triglyceride,CVD: Cardiovascular Disease,GDM: Gestational Diabetes Mellitus,BP: Blood Pressure,SBP: Systolic Blood Pressure,DBP: Diastolic Blood Pressure,PR: Pulse Rate,HDL-C: High-Density Lipoprotein Cholesterol,ALT: Alanine Transaminase,FBS: Fasting Blood Sugar,TC: Total Cholesterol,AST: Aspartate Transaminase,ALP: Alkaline Phosphatase,BUN: Blood Urea Nitrogen
The frequency of the four menarche age groups (≤10,11-12,13-14,15-16 years) were statistically different between the case and the control groups. This were seen for its all components except for Triglyceride (Table 2).
Table 2. Metabolic syndrome components in women 35-70 years old in the Hoveyzeh Cohort Study) HCS (
Category of age at menarche
|
N
|
Metabolic syndrom
|
P_value
|
TG (mg/dl) ≥ 150 mg/dL
|
P_value
|
HDLC (mg/dl) <50
|
P_value
|
BP ≥130/85 mmHg
|
P_value
|
FBS ≥100 mg/dL
|
P_value
|
Abdominal obesity (waist circumstance ≥88)
|
P_value
|
≤ 10
years
|
832
|
412(49.5)
|
0.01
|
309(37.1)
|
0.58
|
386(46.4)
|
0.01
|
257(30.9)
|
0.03
|
386(46.4)
|
0.004
|
737(88.6)
|
0.001
|
11-12 years
|
2001
|
939(46.9)
|
794(39.7)
|
864(43.2)
|
565(28.2)
|
883(44.1)
|
1768(88.4)
|
13-14 years
|
2018
|
880(43.6)
|
781(38.7)
|
836(41.4)
|
517(25.6)
|
805(39.9)
|
1753(86.9)
|
15-16 years
|
979
|
429(43.8)
|
390(39.8)
|
382(39)
|
275(28.1)
|
406(41.5)
|
816(83.4)
|
*Chi-square test
Table 3 shows the odds ratio (OR) and 95% confidence interval (CI) for MetS according to age at menarche of the women in the four groups (≤ 10years, 11-12 years, 13-14 years, 15-16 years), using age at menarche 15-16 years as the reference category. Model 1 shows crude odds ratios of metabolic syndrome for four menarche age groups, so that the odds of metabolic syndrome at menstrual age of ≤ 10 years 1.25 (95% CI (1.04-1.51); P=0.015) times more than age at menarche 15-16 years. Model 2 is adjusted for demographic variables (age, education) and life-style (smoking, and physical activity). The odds of having MetS in at menstrual age of ≤ 10 and 11-12 years were 1.27 (95% CI (1.04-1.54); P=0.01) and 1.20 (95% CI (1.02-1.41); P=0.02) times more than age at menarche 15-16 years, respectively. Model 3 is adjusted for biological measurements (FBS, TG, TCHOL, HDL, SGOT, SGPT and ALK) and DPB, SPB and PR. The odds of having MetS in at menstrual age of ≤10 years was 1.34 (95% CI (1.03-1.74); P=0.02) times more than menstrual age 15-16 years group. Also results in models 4 demonstrated the odds of having MetS in women with age menarche of ≤10 years was 1.30 (95% CI (1.07-1.58); P=0.008) times more than menstrual age 15-16 years group, after adjustment for reproductive variables (gravidity, parity, gestational diabetes and pregnancy hypertension, use of oral contraceptives, use of hormone replacement therapy) (Table3)
Table 3: Odds Ratios (and 95% Confidence Intervals) for MetS by Menarcheal Age in Participants
Menarche (Years)
|
N
|
Case
|
Model 1
|
Model 2
|
Model 3
|
Model 4
|
Model 5
|
OR
|
95% CI
OddsRatio
|
P
|
OR
|
95% CI
OddsRatio
|
P
|
OR
|
95% CI
OddsRatio
|
P
|
OR
|
95% CI
OddsRatio
|
P
|
OR
|
95% CI OddsRatio
|
P
|
|
≤10
|
832
|
412
|
1/25
|
1/04-1/51
|
0/015
|
1/27
|
1/04-1/54
|
0/01
|
1/34
|
1/03-1/74
|
0/02
|
1/30
|
1/07-1/58
|
0/008
|
1/30
|
0/98-1/72
|
0/06
|
|
11-12
|
2001
|
939
|
1/13
|
0/97-1/32
|
0/11
|
1/20
|
1/02-1/41
|
0/02
|
0/95
|
0/76-1/194
|
0/70
|
1/15
|
0/98-1/36
|
0/07
|
0/99
|
0/78-1/25
|
0/94
|
|
13-14
|
2018
|
880
|
0/99
|
0/85-1/15
|
0/91
|
1/12
|
0/95-1/32
|
0/15
|
0/92
|
0/740-1/152
|
0/48
|
1/02
|
0/86-1/20
|
0/78
|
0/99
|
0/78-1/26
|
0/98
|
|
15-16
|
979
|
429
|
1
|
-
|
-
|
1
|
-
|
-
|
1
|
-
|
-
|
1
|
-
|
-
|
1
|
-
|
-
|
|
Model 1: Unadjusted. Model 2: Adjusted demographic variable (Age, Education) AND Life-style (smoking, and Physical activity). Model 3: Adjusted biological FBS, measurements (TG, TCHOL, HDL, SGOT, SGPT, ALK) AND DPB, SPB and PR. Model 4: Adjusted Reproductive variable (Gravidity, parity, has gestational diabetes and pregnancy hypertension, use of oral contraceptives and use of hormone replacement therapy). Model 5: Adjusted Model 2, Model 3 and Model 4